Friday, March 26, 2010

AJDT-PDE builds Redux

AspectJ-aware PDE builds in AJDT have always been a bit of a kludge. So, I'm happy to say that as of Eclipse 3.6 (Helios), things will be changing for the better and AJDT will rely on a different mechanism to perform PDE builds.

PDE, or the Plugin Development Environment, is the tool set that helps developers build plugins for the Eclipse platform itself. In Eclipse 3.5 and earlier, AJDT shipped with its own version of the PDE tools (AJDT-PDE) that were largely a copy of Eclipse's PDE, but with a few key changes so that a different compiler could be plugged in. It is an understatement to say that this was inefficient. The AJDT-PDE had to be re-created for each point release of Eclipse so that it could be re-based off of the new version of PDE. This process was fallible and inevitably, some features of PDE were missing or broken in AJDT-PDE.

I have been working with the PDE team to create a more sustainable solution to AspectJ-aware PDE builds. From AJDT for Eclipse 3.6 and onwards, the AJDT-PDE will be removed. The AspectJ-aware export wizards will be deprecated and the plugin will be redundant. Instead, users can use the standard PDE build, with the following changes to the file of your plugin project:

# required
sourceFileExtensions=*.java, *.aj

# optional
compilerArg=-aspectpath other.jar

The first line specifies that the AspectJ compiler should be used instead of the Java compiler. The second line specifies what file types should be considered source files. And optionally, you can specify a number of command line arguments using the compilerArg property. Only AspectJ-specific arguments like inpath and aspectpath need to be specified here. For all standard Java options, like source and target you can use the standard PDE-Java options javacSource and javacTarget.

From here, you can use the standard PDE export wizards or PDE headless build scripts to build your project. That's it. There is now nothing special needed for AspectJ-aware PDE builds.

Furthermore, it is possible to create your own compiler adapter so that you can use your own custom compiler for your own JVM language (and avoid using javac). You need to do the following:

  1. Implement and delegate to the compiler of your choice

  2. Ensure that this new compiler adapter is on the ant classpath. I recommend using a org.eclipse.ant.core.extraClasspathEntries extension point so that your plugin automatically contributes the classpath to Eclipse's ant runtime. But, you could also specify it in your global ant classpath properties page.

  3. In your file, fill in the proper values for the compilerAdapter, the sourceFileExtensions, and the compilerArg properties.

That's really all there is to it. For all the gory details on how this works see Bug 303960.

Friday, March 19, 2010

Groovy-Eclipse 2.0.1 Released and see you at EclipseCon!

We are proud to release to announce the release of Groovy-Eclipse 2.0.1. This release is primarily a service refresh of 2.0, but there are a couple of interesting new features including debug stack frame filtering and Eclipse 3.5.2 support. You can read the New and Noteworthy.

The update site for the release is here:
This is also a good time to promote my talk at EclipseCon. I will be speaking about Groovy-Eclipse on Wednesday, March 24 at 2pm.

Getting Groovy with Eclipse: Next Generation Tool Support for Dynamic Languages. Come hear how Groovy-Eclipse has extended the JDT compiler to provide deep integration between Groovy and Java. Also hear about how Groovy-Eclipse provides editing support for Groovy's dynamicism through type inferencing.

See you at EclipseCon!

Wednesday, March 17, 2010

AJDT for Helios now available

Just a quick note to let you know that AJDT targeting Helios (Eclipse 3.6) is now available from the following update site:
AspectJ-aware PDE export facilities are currently broken. I am not planning on fixing it. Instead, I have been working with the PDE team on an alternative solution. See Ability to override javac task during pde builds (Bugzilla). I'll write more about this later, but the solution is much more elegant than what is currently available in AJDT for 3.5 and earlier.

Also, as a bonus, this version includes intertype declaration (ITD) -aware Java search. Finally, ITDs are completely first-class citizens in the workspace. I'll write more about this later, too.

Friday, March 5, 2010

Intertype Declaration support in Java projects

A user recently had a problem with Roo and AspectJ. This particular user had a Roo project being referenced by a regular Java project. Roo is a rapid application development tool for Java. It makes heavy use of AspectJ's Intertype Declarations (ITDs). So, all Roo projects re AspectJ projects. And here is where the problem is. When an AspectJ project makes use of ITDs, Java projects that reference it cannot reference the ITDs without errors. Well actually, the Java projects compile and run correctly, but there are spurious error messages that appear in the editor, and ITDs do not appear in content assist.

A simplified version of this problem is below:


Here, there are two projects, an AspectJ project and a Java project. The AspectJ project has an aspect that declares an ITD on a Java class. This Java class and its ITD is then referenced in the Java project. Even though the Java project compiles and runs correctly, an error appears in the editor.

Thankfully, there is a simple fix to this. Open up the .project file for the Java project and add the following line to the nnatures element:

(Note: this line should be the first nature if you want the AJ decorator to appear on the project icon.)

What this does is tell AJDT that this project should be treated like an AspectJ project, but it does not change the compiler, so the Java compiler is still used. The result is that ITDs are now correctly recognized in the editor:


In the future, I'll probably add a quick fix or some other automated way of doing this in future releases of AJDT, but for now this manual process is a reasonable workaround.