Konan
- Kotlin course
- Expert
- Lesson 22/47
- 5 min
Learn the Konan compiler.
What is Konan?
Konan is the name of the Kotlin/Native compiler. It turns Kotlin source into LLVM IR; LLVM then compiles that into native machine code.
Konan uses the LLVM toolchain; each target needs its own toolchain. It runs several LLVM passes during compilation; these optimise for size and speed. Toolchains live under the konan.home directory. Gradle calls Konan automatically via the kotlin-native plugin; you do not run commands by hand. The old name is Konan; today it is usually called the Kotlin/Native compiler, but the tool is still known as Konan.
The Konan toolchain
Konan uses a toolchain for each target. A toolchain contains LLVM and target-specific header files.
Example: the iosArm64 target needs the iOS SDK; linuxX64 needs Linux headers. Konan downloads the needed toolchain under ~/.konan. When a project builds, Konan picks the right toolchain and calls LLVM. This step is transparent to the developer; it runs through Gradle. The first build takes some time because toolchains are downloaded; later builds speed up.
Practice Write Konan info
Define object Konan. Add val version: String = "2.0" and fun info(): String that returns "Konan ${'$'}version". In main, write println(Konan.info()).
Starter code
// add the Konan object
fun main() {
// print Konan.info() result
}Sample solution
object Konan {
val version: String = "2.0"
fun info(): String = "Konan $version"
}
fun main() {
println(Konan.info())
}Expected output
Konan 2.0
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does Konan produce?
- JVM bytecode
- A JSON file
- JavaScript
- LLVM IR Correct answer
Explanation: Konan turns Kotlin source into LLVM IR; LLVM produces machine code.
2 Complete the Konan info
object Konan {
val version: String = "2.0"
fun info(): String = "Konan ${'$'}____"
}object Konan {
val version: String = "2.0"
fun info(): String = "Konan ${'$'}version"
}Explanation: ${'$'}version embeds the version into the string.
3 Match Konan parts
| Term | Meaning |
|---|---|
Konan |
Kotlin/Native compiler |
LLVM |
Machine code producer |
~/.konan |
Toolchain directory |
kotlin native plugin |
Gradle plugin |