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Getting started

By following the instructions on this page, you should be able to generate a SCIP index of your Java codebase using Gradle or Maven. See Supported build tools for an overview of other build tools that we're planning to support in the future.

Install scip-java

The most common way to use scip-java is to run it from CI to upload SCIP indexes after merging a pull request.

The easiest way to install scip-java is to use the Docker image.

Docker image

Use the sourcegraph/scip-java Docker image to run scip-java.

$ docker run -v $(pwd):/home/gradle --env JVM_VERSION=17 sourcegraph/scip-java:latest scip-java index
$ src code-intel upload # (optional) upload index to Sourcegraph

If everything went OK, a index.scip file should exist after the command has finished indexing the project.

The sourcegraph/scip-java Docker image is made available for convenience at the cost of performance. The sourcegraph/scip-java image is a big download because it includes pre-installed versions of Java 8, Java 11, and Java 17. The sourcegraph/scip-java image has slow performance because it needs to download all external dependencies of your codebase on every invocation.

For better performance, we recommend using your own Docker image together with the Java launcher option.

Java 17 is the default Java version in the sourcegraph/scip-java Docker image. Use the following commands to use a different JVM version:

# Java 8
docker run -v $(pwd):/home/gradle --env JVM_VERSION=8 sourcegraph/scip-java:latest scip-java index

# Java 11
docker run -v $(pwd):/home/gradle --env JVM_VERSION=11 sourcegraph/scip-java:latest scip-java index

# Java 17 (default)
docker run -v $(pwd):/home/gradle --env JVM_VERSION=17 sourcegraph/scip-java:latest scip-java index

Java launcher

Use the Java launcher to install scip-java on your local computer or any Docker image with a pre-installed Java version.

# macOS/Linux
curl -fLo coursier https://git.io/coursier-cli \
  && chmod +x coursier \
  && ./coursier launch com.sourcegraph:scip-java_2.13:0.8.13 -- --help

# Windows
bitsadmin /transfer downloadCoursierCli https://git.io/coursier-cli "%cd%\coursier"
bitsadmin /transfer downloadCoursierBat https://git.io/coursier-bat "%cd%\coursier.bat"
./coursier launch com.sourcegraph:scip-java_2.13:0.8.13 -- --help

# macOS Homebrew
brew install coursier/formulas/coursier \
 && coursier launch com.sourcegraph:scip-java_2.13:0.8.13 -- --help

The Java launcher uses Coursier to download scip-java artifacts from Maven Central and build an executable scip-java binary. The jar files for scip-java are downloaded the first time you run the launch command, and they are cached for subsequent runs.

Additional command-line flags can be passed to scip-java after the -- argument. For example, replace --help with index in the command above to run the index subcommand.

Java fat jar

Use the fat jar option to build a standalone scip-java executable. Note that you still need a Java installation to run the scip-java binary.

# macOS/Linux
curl -fLo coursier https://git.io/coursier-cli \
  && chmod +x coursier \
  && ./coursier bootstrap --standalone -o scip-java com.sourcegraph:scip-java_2.13:0.8.13 --main com.sourcegraph.scip_java.ScipJava
./scip-java --help

# Windows
bitsadmin /transfer downloadCoursierCli https://git.io/coursier-cli "%cd%\coursier"
bitsadmin /transfer downloadCoursierBat https://git.io/coursier-bat "%cd%\coursier.bat"
./coursier bootstrap --standalone -o scip-java com.sourcegraph:scip-java_2.13:0.8.13
./scip-java --help

The fat jar uses the Coursier bootstrap command to generate a binary. The fat jar binary includes all dependencies and does not require further access to the internet after installation.

Java library

The scip-java command-line interface is published to Maven Central. You can run the command-line interface as a library by directly invoking the main() method on the com.sourcegraph.scip_java.ScipJava class.

If you're using Gradle.

implementation group: 'com.sourcegraph', name: 'scip-java_2.13', version: '0.8.13'

If you're using Maven.

<dependency>
    <groupId>com.sourcegraph</groupId>
    <artifactId>scip-java_2.13</artifactId>
    <version>0.8.13</version>
</dependency>

If you're using sbt.

scalaVersion := "2.13.6" // Only Scala 2.13 is supported.
libraryDependencies += "com.sourcegraph" %% "scip-java" % "0.8.13"

Run scip-java index

The index command is only supported for Gradle, Maven and sbt. See Supported build tools for more details about other build tools.

Run the scip-java index command to generate a SCIP index for your codebase. This command should automatically infer the structure of your codebase and configure your build tool to generate SCIP.

# At the root of a Gradle, Maven or sbt codebase.
$ scip-java index
...
info: /path/to/index.scip

Build tool	Default command
Gradle	clean compileTestJava compileTestScala compileTestKotlin compileTestKotlinJvm
Maven	--batch-mode clean verify -DskipTests
sbt	sourcegraphEnable sourcegraphScip (via sbt-sourcegraph plugin)
Mill	io.kipp.mill.scip.Scip/generate (via mill-scip plugin)

Customize the build command by passing additional arguments after scip-java index --.

# Example: use `mvn package` instead of `mvn verify`
scip-java index -- --batch-mode -DskipTests package

The index.scip file contains the SCIP index and is ready to be used.

Running scip-java index may perform side-effects on your build like cleaning the compile cache before indexing. This is done to make sure that all source files in the codebase get indexed.

Run scip-java index --help to learn more about the available command-line options.

$ scip-java index --help
USAGE
  scip-java index [OPTIONS ...] -- [TRAILING_ARGUMENTS ...]

DESCRIPTION
  Automatically generate an SCIP index in the current working directory.

OPTIONS
  --help: Boolean                 Print this help message
  --output: Path = "index.scip"   The path where to generate the SCIP index.
  --targetroot: Option[Path]      The directory where to generate SemanticDB
                                  files. Defaults to a build-specific path. For
                                  example, the default value for Gradle is
                                  'build/semanticdb-targetroot' and for Maven
                                  it's 'target/semanticdb-targetroot'
  --[no-]verbose: Boolean = false Whether to enable the -verbose flag in the
                                  SemanticDB compiler plugin.
  --[no-]text: Boolean = false    Whether to enable the -text:on flag in the
                                  SemanticDB compiler plugin.
  --build-tool: Option[String]    Explicitly specify which build tool to use. By
                                  default, the build tool is automatically
                                  detected. Use this flag if the automatic build
                                  tool detection is not working correctly.
  --[no-]cleanup: Boolean = true  Whether to remove generated temporary files on
                                  exit.

TRAILING ARGUMENTS
  Optional. The build command to use to compile all sources. Defaults to a
  build-specific command. For example, the default command for Maven command is
  'clean verify -DskipTests'.To override the default, pass in the build command
  after a double dash: 'scip-java index -- compile test:compile'

EXAMPLES
  # Running the `index` command with no flags should work most of the time.
  $ scip-java index

Supported programming languages

Programming language	Gradle	Maven	sbt	Mill	Tracking issue
Java	✅	✅	✅	✅
Scala	✅	❌	✅	✅	#302
Kotlin	✅	❌	n/a	n/a

Java

The scip-java indexer is implemented as a Java compiler plugin that runs as part of your regular compilation in the build tool. By using Java compiler APIs, scip-java is able to generate accurate indexing information for a broad range of Java versions.

Java version	Support	Tracking issue
Java 7	❌
Java 8	✅
Java 11	✅
Java 17	✅, requires --add-exports

For Java 17 and newer versions, the following JVM options are required:

--add-exports jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED
--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
--add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
--add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
--add-exports jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED

Scala

Scala version support should always match the Scala versions that are supported by Metals, the Scala language server.

Scala version	Goto definition	Find references	Hover
Scala 2.10.x	❌	❌	❌
Scala 2.11.x	✅	✅	✅
Scala 2.12.x	✅	✅	✅
Scala 2.13.x	✅	✅	✅
Scala 3.x	✅	✅	❌

Scala.js and Scala Native have equal support as Scala on the JVM.

Kotlin

The Kotlin support in scip-java is less mature compared to the Java and Scala support. Don't hesitate to report issues at https://github.com/sourcegraph/scip-java if you encounter issues using the Kotlin support.

Supported build tools

It's possible to use scip-java with any Java build tool. Some build tools can be automatically configured by the scip-java index command while other build tools may require manual configuration.

Automatic configuration

Please open an issue if your build tool is not listed in the table below. Feel free to subscribe to the tracking issues to receive updates on your build tool.

Build tool	Java	Scala	Kotlin	Tracking issue
Maven	✅	❌	❌
Gradle	✅	✅	✅
sbt	✅	✅	n/a
Ant	❌	❌	❌	sourcegraph/scip-java#305
Bazel	✅	✅	❌
Buck	❌	❌	❌	sourcegraph/scip-java#99
Mill	✅	✅	❌

✅: automatic indexing is fully supported. Please report a bug if the scip-java index command does not work on your codebase.

❌: automatic indexing is not supported but (!) you may still be able to use scip-java by configuring it manually using the instructions here.

Manual configuration

See the manual configuration guide for instructions on how to configure scip-java to work with any build tool.

Gradle

The scip-java index build should be able to automatically index most Gradle projects. You Gradle build must contain one of the following files in the same directory where scip-java index gets invoked.

• settings.gradle
• gradlew
• build.gradle
• build.gradle.kts

The following Gradle integrations are not yet supported:

Integration	Supported	Tracking issue
Android	❌	sourcegraph/scip-java#177
Kotlin	✅
Scala	✅

Maven

The scip-java index build should be able to automatically index most Maven projects. Your Maven build must contain a pom.xml file in the same directory where scip-java index gets invoked.

The following Maven integrations are not yet supported:

Integration	Supported	Tracking issue
scala-maven-plugin	❌	sourcegraph/scip-java#301
scalor-maven-plugin	❌	sourcegraph/scip-java#301
kotlin-maven-plugin	❌	sourcegraph/scip-java#304

sbt

The scip-java index build should be able to automatically index most sbt projects, with the following caveats:

Integration	Supported	Recommendation
sbt <v0.13.17	❌	Upgrade to sbt v0.13.17

Mill

The scip-java index build should be able to automatically index most Mill projects, with the following caveats:

Integration	Supported	Recommendation
Mill <v0.10.0	❌	Upgrade to Mill >= v0.10.0
Mill <v0.10.6	Only supports Scala	Upgrade to Mill >= v0.10.6 for Java support

Bazel

Bazel is supported by scip-java but it requires custom configuration to work correctly. Note that the scip-java index command does not automatically index Bazel builds.

The Bazel integration for scip-java is specifically designed to be compatible with the Bazel build cache to enable incremental indexing. To achieve this, scip-java must be configured in WORKSPACE and BUILD files. The scip-java repository contains an example for how to configure everything.

• WORKSPACE: adds the required dependencies to be able to run scip-java itself.
• BUILD: configured java_library and java_binary targets to be indexed with scip-java.

Don't hesitate to open an issue in the scip-java repository if you have any questions about using scip-java with Bazel builds.