insert native lib into jar

cmd/plt-build/build.gradle.kts

@@ -29,6 +29,11 @@ dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:${kotlinCoroutinesVersion}")
 }
 
+sourceSets.main {
+    resources {
+        srcDirs("src/main/resources", "build/natives")
+    }
+}
 kotlin {
     jvmToolchain(24)
 }
@@ -36,4 +41,12 @@ kotlin {
 tasks.test {
     useJUnitPlatform()
 }
-project.layout.buildDirectory.set(file("../../build"))
+tasks.register<Exec>("compileNativeLib") {
+    val java_home = System.getProperty("java.home")
+    environment("CGO_CFLAGS" to "-I$java_home/include -I$java_home/include/linux")
+    workingDir("src/main/go")
+    commandLine("go", "build", "-linkshared", "-buildmode=c-shared", "-o", layout.buildDirectory.get().dir("natives").file("pltbuild.so"))
+}
+tasks.processResources {
+    dependsOn += "compileNativeLib"
+}

cmd/plt-build/src/main/go/main.go

@@ -1,6 +1,5 @@
-package _go
+package main
 
-//#cgo CFLAGS: -I "$JAVA_HOME/include" -I "$JAVA_HOME/include/linux"
 //#include "pltbuild.h"
 import "C"
 import (

cmd/plt-build/src/main/kotlin/moe/rosa/planterette/jni/GoFile.kt

@@ -1,5 +1,19 @@
 package moe.rosa.planterette.jni
 
+import java.io.File
+import java.nio.file.Files
+
 object GoFile {
     external fun write(fd: Int, str: String)
+    init {
+        val libname = "pltbuild.so"
+        val url = GoFile::class.java.getResource("/$libname")
+        val tmpDir = Files.createTempDirectory("pltbuild").toFile()
+        tmpDir.deleteOnExit()
+        val nativeLibTmpFile = File(tmpDir, libname)
+        url?.openStream().use {
+            Files.copy(it!!, nativeLibTmpFile.toPath())
+        }
+        System.load(nativeLibTmpFile.absolutePath)
+    }
 }