DoppioVM: A JVM in Coffeescript
Doppio is a double shot of espresso. In this case it's also a JVM written in Coffeescript.
It began life as a Mid-term project for CS 691ST, Spring 2012 at UMass Amherst.
To try Doppio now, head to the live demo page.
Getting & Building the Code
After git clone, do
git submodule update --init --recursive
Java programs need the Java Class Library. This generally lives in
an archive named rt.jar, which comes with the JRE. Note that you
do not need a JDK to run Doppio, but our automated tests do require
a Java compiler and disassembler (javac and javap, respectively).
To provide the JCL for Doppio, simply unzip the class library in
third_party/classes.
On OS X Lion, rt.jar is confusingly named classes.jar:
cd third_party/classes
unzip /System/Library/Frameworks/JavaVM.framework/Classes/classes.jar
We've opted to patch the java.util.zip package with Jazzlib,
a pure-Java third-party implementation.
Download the classes and copy them over the files in
third_party/classes/java/util/zip/.
Use Coffeescript v1.2.0:
npm install -g coffee-script@1.2.0
Run coffee -wc */*.coffee & to auto-generate javascript sources if you make any changes to the code.
If you want to run the console-based frontend, you'll need the optimist node.js library:
npm install optimist
To build the release copy of the code, you'll need rdiscount as well.
Finally, to ensure that everything is set up properly, run:
make test
Usage
To run Doppio on localhost, run . startup.sh, or start the browser frontend manually:
cpp -P -traditional-cpp browser/index.html index.html
ruby webrick.rb --dev
To get the optimized release version:
make release
ruby webrick.rb --release
Then point your browser to http://localhost:8000/.
The code can also be run from the console. For example:
./console/disassembler.coffee test/Println.class
./console/runner.coffee test/Println
Testing
Run the automated test-runner to check runtime and disassembler output:
make test
The tests can take a while to complete, so consider running them in parallel (make -j4).