== Debugger in [[NetBeans]] 8.1 ==

[[NetBeans]] 8.1 and newer ships with support for debugging of [[Truffle]] languages. Here is a promotional video demonstrating how to use such feature, but you can try that too! Just get the most recent build of [[NetBeans]], install the [[Truffle]] Debugging Support module and get the sources:

* Download latest daily build of [[NetBeans]] - tested on '''netbeans-trunk-nightly-201510210002-javase.zip''' downloaded from http://bits.netbeans.org/download/trunk/nightly/2015-10-21_00-02-28/zip/
* Install [[Truffle]] Debugging Support: Go to ''Tools/Plugins/Available Plugins'' and seek for ''Truffle'', then install.
* Get the latest [[GraalVM]] build from the OTN: http://www.oracle.com/technetwork/oracle-labs/program-languages/overview/index.html

==== Installing [[Maven]] Bits and Working with Sources ====

Assuming your [[GraalVM]] is installed in directory ''$GRAAL_VM'', continue by installing essential [[Truffle]] binaries into your local [[Maven]] repository:

<source lang="bash">
$ $GRAAL_VM/bin/maven_install_graalvm
</source>

and then you can work with the sources. First of all obtain them and switch to the correct (known to work at present time) revision:

<source lang="bash">
$ hg clone http://source.apidesign.org/hg/truffledebugdemo/
$ cd truffledebugdemo
$ hg up -C GraalVM-0.9
</source>

With the sources you can now use the command line or the IDE to work with them:

<source lang="bash">
# compile:
$ JAVA_HOME=$GRAAL_VM mvn clean install
# execute
$ JAVA_HOME=$GRAAL_VM mvn exec:exec
factorial(5) = 120
</source>

The sample prints out value of factorial for five computed in four different ([[Java]], [[Ruby]], [[JavaScript]] and our testing simple language) [[language]]s.

==== Debugging from [[NetBeans]] ====

Make sure [[NetBeans]] is running on the [[GraalVM]]:

<source lang="bash">
$ /netbeans8.1/bin/netbeans --jdkhome $GRAAL_VM
</source>

Open the project sources in the IDE (File/Open Project, select the '''truffledebugdemo''' directory). Open ''MixLanguages.java'' source file. Put breakpoint to ''MixLanguages.java'' line 37 that invokes the global ''factorial'' symbol and debug the project (Debug/Debug Project or press Ctrl-F5). Once the breakpoint is hit, you can step-into (F7), you'll be in [[JavaScript]]. If you continue stepping in you'll get into ''simple language'' and then also into [[Ruby]]. Values of local variables will be available. Enjoy:

{{#ev:youtube|ewdzDqPsn38}}


[[Category:Video]]