Using javac to generate header

jni/build.gradle.kts

@@ -1,104 +1,27 @@
 plugins {
-    kotlin("multiplatform") // version "1.4-M2-mt"
-    id("com.android.library")
-    `maven-publish`
+    kotlin("jvm")
 }
 
-val currentOs = org.gradle.internal.os.OperatingSystem.current()
-
 kotlin {
     explicitApi()
-
-    val commonMain by sourceSets.getting {
-        dependencies {
-            api(rootProject)
-            implementation(kotlin("stdlib-common"))
-        }
-    }
-    val commonTest by sourceSets.getting {
-        dependencies {
-            implementation(kotlin("test-common"))
-            implementation(kotlin("test-annotations-common"))
-        }
-    }
-
-    jvm {
-        compilations.all {
-            kotlinOptions.jvmTarget = "1.8"
-        }
-        (tasks[compilations["main"].processResourcesTaskName] as ProcessResources).apply {
-            dependsOn("copyJni")
-            from(buildDir.resolve("jniResources"))
-        }
-        compilations["main"].dependencies {
-            implementation(kotlin("stdlib-jdk8"))
-        }
-        compilations["test"].dependencies {
-            implementation(kotlin("test-junit"))
-        }
-    }
-
-    android {
-        publishLibraryVariants("release", "debug")
-        compilations.all {
-            kotlinOptions.jvmTarget = "1.8"
-        }
-        sourceSets["androidMain"].dependencies {
-            implementation(kotlin("stdlib-jdk8"))
-        }
-        sourceSets["androidTest"].dependencies {
-            implementation(kotlin("test-junit"))
-            implementation("androidx.test.ext:junit:1.1.1")
-            implementation("androidx.test.espresso:espresso-core:3.2.0")
-        }
-    }
-
-    sourceSets.all {
-        languageSettings.useExperimentalAnnotation("kotlin.RequiresOptIn")
-    }
 }
 
-android {
-    defaultConfig {
-        compileSdkVersion(30)
-        minSdkVersion(21)
-        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
-        externalNativeBuild {
-            cmake {}
-        }
-    }
-
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
-    }
-
-    externalNativeBuild {
-        cmake {
-            setPath("src/androidMain/CMakeLists.txt")
-        }
-    }
-    ndkVersion = "21.3.6528147"
-
-    sourceSets["main"].manifest.srcFile("src/androidMain/AndroidManifest.xml")
-
-    afterEvaluate {
-        tasks.withType<com.android.build.gradle.tasks.factory.AndroidUnitTest>().all {
-            enabled = false
-        }
-    }
+dependencies {
+    api(rootProject)
+    implementation(kotlin("stdlib-jdk8"))
 }
 
-val copyJni by tasks.creating(Sync::class) {
-    dependsOn(":native:buildSecp256k1Jvm")
-    from(rootDir.resolve("native/build/linux/libsecp256k1-jni.so")) { rename { "libsecp256k1-jni-linux-x86_64.so" } }
-    from(rootDir.resolve("native/build/darwin/libsecp256k1-jni.dylib")) { rename { "libsecp256k1-jni-darwin-x86_64.dylib" } }
-    from(rootDir.resolve("native/build/mingw/secp256k1-jni.dll")) { rename { "secp256k1-jni-mingw-x86_64.dll" } }
-    into(buildDir.resolve("jniResources/fr/acinq/secp256k1/jni/native"))
-}
-
-afterEvaluate {
-    configure(listOf("Debug", "Release").map { tasks["externalNativeBuild$it"] }) {
-        dependsOn(":native:buildSecp256k1Android")
+val generateJniHeaders by tasks.creating(JavaCompile::class) {
+    group = "build"
+    classpath = sourceSets["main"].compileClasspath
+    destinationDir = file("${buildDir}/generated/jni")
+    source = sourceSets["main"].java
+    options.compilerArgs = listOf(
+        "-h", file("${buildDir}/generated/jni").absolutePath,
+        "-d", file("${buildDir}/generated/jni-tmp").absolutePath
+    )
+    // options.verbose = true
+    doLast {
+        delete(file("${buildDir}/generated/jni-tmp"))
     }
 }