Kotlin/Native FAQ

How do I run my program?

Define a top-level function fun main(args: Array<String>) or just fun main() if you are not interested in passed arguments, please ensure it's not in a package. Also, compiler switch -entry could be used to make any function taking Array<String> or no arguments and return Unit as an entry point.

What is Kotlin/Native memory management model?

Kotlin/Native uses an automated memory management scheme that is similar to what Java or Swift provide.

Learn about the Kotlin/Native memory manager

How do I create a shared library?

Use the -produce dynamic compiler option or binaries.sharedLib() in your Gradle build file:

kotlin {
    iosArm64("mylib") {
        binaries.sharedLib()
    }
}

It produces a platform-specific shared object (.so on Linux, .dylib on macOS, and .dll on Windows targets) and a C language header, allowing the use of all public APIs available in your Kotlin/Native program from C/C++ code.

Complete the Kotlin/Native as a dynamic library tutorial

How do I create a static library or an object file?

Use the -produce static compiler option or binaries.staticLib() in your Gradle build file:

kotlin {
    iosArm64("mylib") {
        binaries.staticLib()
    }
}

It produces a platform-specific static object (.a library format) and a C language header, allowing you to use all the public APIs available in your Kotlin/Native program from C/C++ code.

How do I run Kotlin/Native behind a corporate proxy?

As Kotlin/Native needs to download a platform specific toolchain, you need to specify -Dhttp.proxyHost=xxx -Dhttp.proxyPort=xxx as the compiler's or gradlew arguments, or set it via the JAVA_OPTS environment variable.

How do I specify a custom Objective-C prefix/name for my Kotlin framework?

Use the -module-name compiler option or matching Gradle DSL statement.

kotlin {
    iosArm64("myapp") {
        binaries.framework {
            freeCompilerArgs += listOf("-module-name", "TheName")
        }
    }
}

kotlin {
    iosArm64("myapp") {
        binaries.framework {
            freeCompilerArgs += ["-module-name", "TheName"]
        }
    }
}

How do I rename the iOS framework?

The default name is for an iOS framework is <project name>.framework. To set a custom name, use the baseName option. This will also set the module name.

kotlin {
    iosArm64("myapp") {
       binaries {
          framework {
              baseName = "TheName"
          }
       }
    }
}

How do I enable bitcode for my Kotlin framework?

Bitcode embedding was deprecated in Xcode 14 and removed in Xcode 15 for all Apple targets. The Kotlin/Native compiler does not support bitcode embedding since Kotlin 2.0.20.

If you're using earlier versions of Xcode but want to upgrade to Kotlin 2.0.20 or later versions, disable bitcode embedding in your Xcode projects.

How do I reference objects safely from different coroutines?

To safely access or update an object across multiple coroutines in Kotlin/Native, consider using concurrency-safe constructs, such as @Volatile and AtomicReference.

Use @Volatile to annotate a var property. This makes all reads and writes to the property's backing field atomic. In addition, writes become immediately visible to other threads. When another thread accesses this property, it observes not only the updated value but also the changes that happened before the update.

Alternatively, use AtomicReference, which supports atomic reads and updates. On Kotlin/Native, it wraps a volatile variable and performs atomic operations. Kotlin also provides a set of types for atomic operations tailored to specific data types. You can use AtomicInt, AtomicLong, AtomicBoolean, AtomicArray, as well as AtomicIntArray and AtomicLongArray.

For more information about access to shared mutable state, see the Coroutines documentation.

How can I compile my project with unreleased versions of Kotlin/Native?

First, please consider trying preview versions.

In case you need an even more recent development version, you can build Kotlin/Native from source code: clone Kotlin repository and follow these steps.

Last modified: 09 April 2025