Checker Framework Support for Eclipse

An LSP4E Eclipse plugin connecting to the Checker Framework language server.

First-Time Setup Instructions

Download Eclipse for your platform and install it.

Make sure the following three plugins are installed:

• "Eclipse PDE Plug-in Developer Resources"
• "LSP4J SDK"
• "Language Server Protocol client for Eclipse IDE (Incubation)"

Click Help - Install New Software - Install then search for "PDE" and "LSP" to find them. Also install any needed dependencies. Eclipse needs a restart after any installation or update.

Clone or download this repository, e.g. from https://github.com/eisopux/checker-framework-eclipse.git and open the project in Eclipse.

When opening the project for the first time, check the project build path. Right click the project in Package Explorer, select Build Path - Configure Build Path. In the Java Build Path - Libraries tab under Plug-in Dependencies you should see no errors. If there are any errors, go back to Install New Software and install any missing dependencies.

You can then run the project as an Eclipse Application. Another Eclipse window will open up.

The plugin's default preference settings are empty strings and must be specified by the user before the language server can run. When the plugin first starts, you may see an Exception and/or error message that the checker path is invalid. To fix this, go to Preferences in the opened-up plugin project, click Checker Framework LSP, and set the checker path (folder containing Checker Framework and language server) and which type checker to use. Then, restart Eclipse to allow the plugin to see the changes.

Note: any changes to the preference text fields require a restart to allow the plugin to see the changes.

Note 2: make sure the folder specified in the checker path only contains one instance of the language server and the Checker Framework. There is currently no way of specifying which version to use in the plugin if there are multiple versions of the files.

Using this Plugin

You can test the plugin by clicking the Run button in the Eclipse Plugin Development IDE (PDE).

The plugin will automatically start the language server when a .java file is opened. To re-run the checker, either save the changes in the file or re-open the file.

If the checker path specified is missing the Checker Framework or language server, the plugin will automatically try and download the newest versions of the Checker Framework and language server into the specified path and run the language server.

Currently, only one type checker can be used at a time.

To change which checker to use, edit the checker type in the Preferences Page and change the text field. Please restart after making the change to have it take effect.

Note: the red underlining from errors detected by the language server may underline the wrong word if tabs exist in the erroneous line due to Eclipse interpreting tabs differently than the language server.

Exporting the Plugin

To export the plugin in order to deploy it, right click on the project in the Project Explorer Panel and click Export. Then, click into Plugin Development and select Deployable Plug-ins and Fragments. Click Next, then select the destination folder to generate the JAR file for the plugin.

Installing the Plugin

To install the plugin, select the JAR file of the plugin and drop it into the dropins/eclipse/plugins directory under your target Eclipse directory. Then, run that Eclipse instance and the plugin should be up and running.

References

• checker-framework-languageserver