Building WPILib is very straightforward. WPILib uses Gradle to compile. It only has a few dependencies on outside tools, including the ARM cross compiler.
Clone the WPILib Repo. If the toolchains are not installed, install them, and make sure they are available on the system PATH.
All build steps are executed using the Gradle wrapper, gradlew. Each target that Gradle can build is referred to as a task. The most common Gradle task to use is build. This will build all of the outputs created by WPILib. To run, open a console and cd into the cloned WPILib directory. Then:
./gradlew build
To build a specific subproject, such as wpilibc, you must access the subproject and run the build task only on that project. Accessing a subproject in Gradle is quite easy. Simply use :subproject_name:task_name with the Gradle wrapper. For example, building just wpilibc:
./gradlew :wpilibc:build
The gradlew wrapper only exists in the root of the main project, so be sure to run all commands from there. All of the subprojects have build tasks that can be run. Gradle automatically determines and rebuilds dependencies, so if you make a change to the HAL and then run :wpilibc:build, the HAL will be rebuilt, then wpilibc.
There are a few tasks other than build available. To see them, run the meta-task tasks. This will print a list of all available tasks, with a description of each task.
If you are building to test with the eclipse plugins or just want to export the build as a Maven-style dependency, simply run the publish task. This task will publish all available packages to ~/releases/maven/development. If you need to publish the project to a different repo, you can specify it with -Prepo=repo_name. Valid options are:
The following maven targets a published by this task: