IDE support

Kotlin plugins that support 1.8.0-RC2 are available for:

Kotlin/JVM

• Removed the old backend. (The -Xuse-old-backend compiler option is no longer supported).

• Added support for Java 19 bytecode.

Kotlin/Native

• Added support for Xcode 14.1 and watchosDeviceArm64 target.

• Added support for new annotations to improve Objective-C and Swift interoperability:

  • @ObjCName

  • @HiddenFromObjC

  • @ShouldRefineInSwift

• Added improvements to the CocoaPods Gradle plugin so that registered Kotlin frameworks are now dynamically linked by default.

Kotlin/JS

• Stabilized the IR compiler and set incremental compilation to be used by default.

• Deprecated the old backend.

• Added additional reporting options for when yarn.lock is updated during the CI process.

• Updated the Gradle plugin so that kotlin.js.browser.karma.browsers property can be used to set browser test targets.

Kotlin Multiplatform

• Added new Android source set layout that can be enabled in Gradle plugin with kotlin.mpp.androidSourceSetLayoutVersion=2.

• Added new naming schema for KotlinSourceSet entities.

• Changed the naming scheme of compilation configurations created by the Kotlin Multiplatform Gradle plugin.

Gradle

• Ensured compatibility with Gradle 7.3.

• Added the option to disable daemon fallback by using kotlin.daemon.useFallbackStrategy.

• Exposed available Kotlin compiler options as Gradle lazy properties.

• Updated minimum supported Gradle version to 6.8.3.

• Updated minimum supported Android Gradle plugin version to 4.1.3.

Compiler

Updated the Lombok compiler plugin so that it now supports the @Builder annotation.

Standard library

• Updated the JVM target of the libraries in Kotlin distribution to version 1.8:

  • The contents of the artifacts kotlin-stdlib-jdk7 and kotlin-stdlib-jdk8 have been moved into kotlin-stdlib.

• Stabilized extension functions for java.util.Optional.

• Stabilized functions:

  • cbrt()

  • toTimeUnit()

  • toDurationUnit()

• Added new experimental extension functions for java.nio.file.path that can recursively copy or delete directory content. Opt-in is required (see details below), and you should use them only for evaluation purposes.

• Added new experimental functionality to TimeMarks, allowing elapsedNow to be read from multiple TimeMarks simultaneously. Opt-in is required (see details below), and you should use them only for evaluation purposes.

How to update to Kotlin 1.8.0-RC2

You can install Kotlin 1.8.0-RC2 in the following ways:

• If you use the Early Access Preview update channel, the IDE will suggest automatically updating to 1.8.0-RC2 as soon as it becomes available.

• If you use the Stable update channel, you can change the channel to Early Access Preview at any time by selecting Tools | Kotlin | Configure Kotlin Plugin Updates in your IDE. You'll then be able to install the latest preview release. Check out these instructions for details.

Once you've installed 1.8.0-RC2, don't forget to change the Kotlin version to 1.8.0-RC2 in your build scripts.

Learn more

For more detail about the contents of this release, see our changelog.