GNU/Andrew’s Blog

Congratulations to the IcedTea team (Lillian Angel, Gary Benson, Tom Fitzsimmons, Joshua Sumali, Andrew Haley, Mark Wielaard) on another release. The OpenJDK version is only one drop further on (b09 as opposed to b08) but there are lots of other IcedTea related changes including the import of MIDI support via Gervill and a Linux/SPARC HotSpot port, not to mention numerous fixes and jtreg-based testing. Gentoo users can already find an ebuild for this in my overlay: http://fuseyism.com/hg/libre_java_overlay.

Unfortunately, creating this ebuild immediately showed up a few issues with the release. The first was rather peculiar, it seems the jar executable from IcedTea 6 1.1 couldn’t handle the @ option used to build the rt.jar file:

(cd /var/tmp/portage/dev-java/icedtea6-1.2/work/icedtea6-1.2/openjdk-ecj/control/build/linux-amd64/classes
&& /bin/cat /var/tmp/portage/dev-java/icedtea6-1.2/work/icedtea6-1.2/openjdk-ecj/control/build/linux-amd64/tmp/jarfilelists/rt_jar_list
| /usr/lib/jvm/icedtea6-1.1/bin/jar c0mf@
/var/tmp/portage/dev-java/icedtea6-1.2/work/icedtea6-1.2/openjdk-ecj/control/build/linux-amd64/tmp/manifest.tmp
/var/tmp/portage/dev-java/icedtea6-1.2/work/icedtea6-1.2/openjdk-ecj/control/build/linux-amd64/tmp/rt-orig.jar
           -J-Xmx896m -J-Xms128m -J-XX:PermSize=32m
-J-XX:MaxPermSize=160m)
Illegal option: @
Usage: jar {ctxui}[vfm0Me] [jar-file] [manifest-file] [entry-point]
[-C dir] files ...

Interestingly, using gjar does work, so for the time being I’ve enforced the use of gcj-4.3 in the ebuild, and used gjar from this. Patching it so that it becomes /usr/lib/jvm/icedtea6-1.1/bin/jar c0mf should also work.

The other issue I ran into was with the plugin option. Gentoo’s econf system specifies all the configure options it uses even if the values are the defaults, due to the way it is automated. So even though the plugin is enabled by default, –enable-gcjwebplugin still gets passed to the build. However, it seems this actually disables it for IcedTea6. I patched this as:

diff -r 3fe8a0881e86 configure.ac
--- a/configure.ac      Wed May 28 11:29:51 2008 -0400
+++ b/configure.ac      Fri May 30 00:53:44 2008 +0100
@@ -101,13 +101,13 @@ AC_ARG_ENABLE([gcjwebplugin],
 AC_ARG_ENABLE([gcjwebplugin],
              [AS_HELP_STRING([--disable-gcjwebplugin],
                              [Disable compilation of browser plugin])],
-             [ENABLE_PLUGIN="$val"], [ENABLE_PLUGIN='yes'])
+             [ENABLE_PLUGIN="${enableval}"], [ENABLE_PLUGIN='yes'])
 AC_SUBST(ENABLE_PLUGIN)

 AC_ARG_ENABLE([docs],
              [AS_HELP_STRING([--disable-docs],
                              [Disable generation of documentation])],
-             [ENABLE_DOCS="$val"], [ENABLE_DOCS='yes'])
+             [ENABLE_DOCS="${enableval}"], [ENABLE_DOCS='yes'])
 AM_CONDITIONAL([ENABLE_DOCS], [test x$ENABLE_DOCS = xyes])

 AC_ARG_WITH([icedtea],

This wouldn’t have been noticed because usually you either stick with the default (which does turn on the plugin) or, if an option is specified, you disable it (which happens). The problem is that specifying either form of the gcjwebplugin option disables it, including the one that’s meant to enable it.

With these two issues fixed, IcedTea6 1.2 can be installed on Gentoo.

It seems a lot of projects and distributions are seeing new releases either now or in the very near future. This week, we had a very quiet minor release of GJDoc, the GNU Classpath equivalent to javadoc. 0.7.9 includes a few changes that were previously only available in CVS, but the main one is a small fix that allows Classpath 0.97.1 documentation to be built. Our minor .1 release for 0.97 fixed a bug where the JSR166 code was not being included in the documentation build. With this fixed, it turns out gjdoc would no longer build the documentation as java.util.concurrent.TimeUnit is a rather complicated enumeration that our hacks can’t bypass. Michael Koch, in packaging GJDoc for Debian, was kind enough to point out that having the current release of GJDoc not being able to build documentation for the current release of Classpath was a bad thing. A quick release fixed this by pushing out the fix I made for this issue back in March. Of course, you can now use javadoc for IcedTea/OpenJDK to build the documentation instead; with another Free JDK about, there’s no need to just rely on GJDoc.

I do wonder what the long term future for GJDoc should be. It only works with GNU Classpath at present through a nasty bunch of hacks which cause the parser to skip chunks of the input. It really needs a major cleanup and to be made to work properly with 1.5 code. Thomas Fitzsimmons suggested we should merge it into the GNU Classpath codebase which seems a good idea, as it means we don’t run into this same revision hole we just did. However, it is worth maintaining GJDoc at all? For me, the main features it has over the OpenJDK javadoc are in speed and the look of the output. A key feature is also that it it plays nicer with Free Software i.e. it includes an option to include the source code with syntax highlighting. You can see the output for Classpath 0.97 online.

JikesRVM is also stepping up for a new release, 2.9.3, and this will be the first to showcase the new Classpath support for a non-copying unsynchronised StringBuilder. This is designed for local method usage where the builder will be converted to an immutable String object rather than leaving the method. As a result, I’ve been rushing to get it in a releasable state, as I know there’s a nasty bug lurking in the older patches JikesRVM has been using recently. I managed to do this today after we fixed a build issue. It seems the javah in OpenJDK6 outputs differently named header files to those JikesRVM implicitly depends on. We fixed this by making this dependency explicit as it should be, but perhaps this also uncovered an OpenJDK6 bug. I’m not sure where we should be filing these yet, so I just posted to jdk6-dev.

It’s also nice to hear that Ubuntu has just shipped with IcedTea6 included. Fedora 9 will also ship early next month (May 13th) with similar support and an OpenSUSE build is in the works. It’s nice to see Java support making it into the mainstream, thanks to Sun’s recent moves to make their JDK Free Software. On the less positive side, it seems that Gentoo won’t see support for IcedTea6 anytime soon. The Java Gentoo developers seem to be on a strange mission to support only the proprietary Java solutions (pretty much an inverse of what Fedora, Ubuntu and Debian do). In porting my IcedTea6 ebuild from the Libre Java overlay to their own overlays, they seem to have decided to drop support for GCJ… I’m not even going to go into how dumb this action is, as I could be here a while. Suffice to say, I don’t see how IcedTea6 can be bootstrapped without GCJ, let alone how they expect to then build it on architectures like PPC, PPC64 and ARM, as we’ve seen happen on the OpenJDK distro mailing list. It seems a very odd move for a distribution supposedly built on compiling things from source…

Over the last week, I’ve been getting Gentoo and Free Java up and running on my new x86_64 box, a process which has culminated in the creation of my own overlay:

http://fuseyism.com/hg/libre_java_overlay

For those unfamiliar with Gentoo, an overlay is an additional set of packages (known in Gentoo as ebuilds, as for a source-based distribution the packages are essentially build scripts) which can be placed over the top of the main system tree to provide newer/better versions of existing builds and completely new ones too.

The Libre Java overlay includes a build for GCJ 4.3 (adapted from the one for an alpha snapshot in the java-gcj-overlay) and one for IcedTea6. Unfortunately, Gentoo’s Java support seems incredibly broken — the main stable and experimental (~) distributions don’t include OpenJDK or IcedTea, and the stable versions of GNU Classpath and VMs like CACAO and JamVM are ancient. GNU Classpath is still on 0.90, which is older than the one in Debian stable. It also tries to pull in the proprietary JDK by default; I recommend Free Java Gentoo users add:

dev-java/sun-jdk
dev-java/ibm-jdk
dev-java/jrockit
dev-java/diablo
dev-java/sun-jre-bin
dev-java/blackdown-jdk

to package.mask to avoid accidentally installing proprietary software on their machines. Unfortunately, stable versions of portage have yet to honour any license scheming, although it is in the unstable version. If you use Gentoo, feel free to try out the ebuilds from my overlay and give feedback. To use it, just get Mercurial (emerge mercurial), clone the repository:

hg clone http://fuseyism.com/hg/libre_java_overlay

and then add the following to /etc/make.conf:

PORTDIR_OVERLAY=<location you downloaded libre_java_overlay to>

The build process for IcedTea6 is fully documented on the IcedTea wiki.