Kotlin Native

See

• https://kotlinlang.org/docs/native-get-started.html

• https://github.com/kgit2/c-interop-klib

• https://github.com/Kotlin/kmp-native-wizard

Go to https://github.com/JetBrains/kotlin/releases/tag/v2.1.20, download kotlin-native-prebuilt-macos-x86_64-2.1.20.tar.gz. Unzip it and put its bin to the PATH:

export PATH=/Users/fangjun/software/

./code/native/hello.kt

fun main() {
    println("Hello, Kotlin/Native!")
}

kotlinc-native ./hello.kt -o hello

Next, we can run ./hello.kexe.

sherpa-onnx

The sherpa-onnx-c-api.def file:

headers = sherpa-onnx/c-api/c-api.h
headerFilter = sherpa-onnx/c-api/c-api.h
compilerOpts = -I /Users/fangjun/open-source/sherpa-onnx
package = sherpa_onnx
linkerOpts = -L /Users/fangjun/open-source/sherpa-onnx/build/lib -lsherpa-onnx-c-api

The main.kt:

import kotlinx.cinterop.*
import sherpa_onnx.*

fun main() {
  print("hello")
}

The command:

cinterop -def ./sherpa-onnx-c-api.def -o libsherpa_onnx_c_api.klib
kotlinc-native  ./main.kt -l   libsherpa_onnx_c_api.klib

# a.txt contains the kotlin code for our c api
klib dump-metadata ./libsherpa_onnx_c_api.klib -print-signatures true > a.txt

char

In C extern usigned char my_c_byte.

In kotlin, there is a implicit extern var my_c_byte: ByteVar. The variable type in Kotlin is ByteVar.

var bytePtr: NativePtr = my_c_byte.ptr

// Note: bytePtr.pointed == my_c_byte

// Read it
val byteValue: Byte = bytePtr.pointed.value

// Change it
bytePtr.pointed.value = 0x42

// Read it again
val newByteValue: Byte = bytePtr.pointed.value