[MPP, KPM]: Generate KpmNativeVariants from KonanTargets

libraries/tools/kotlin-gradle-plugin-dsl-codegen/build.gradle.kts

@@ -1,5 +1,3 @@
-import org.gradle.jvm.tasks.Jar
-
 plugins {
     kotlin("jvm")
 }
@@ -20,7 +18,12 @@ val generateAbstractBinaryContainer by generator(
     sourceSets["main"]
 )
 
-listOf(generateMppTargetContainerWithPresets, generateAbstractBinaryContainer).forEach {
+val generateKpmNativeVariants by generator(
+    "org.jetbrains.kotlin.generators.gradle.dsl.KpmNativeVariantCodegenKt",
+    sourceSets["main"]
+)
+
+listOf(generateMppTargetContainerWithPresets, generateAbstractBinaryContainer, generateKpmNativeVariants).forEach {
     it.systemProperty(
         "org.jetbrains.kotlin.generators.gradle.dsl.outputSourceRoot",
         project(":kotlin-gradle-plugin").projectDir.resolve("src/main/kotlin").absolutePath

libraries/tools/kotlin-gradle-plugin-dsl-codegen/src/main/kotlin/org/jetbrains/kotlin/generators/gradle/dsl/codegenUtils.kt

@@ -32,9 +32,18 @@ internal fun TypeName.renderErased(): String =
 internal fun TypeName.collectFqNames(): Set<String> =
     setOf(fqName) + typeArguments.flatMap { it.collectFqNames() }.toSet()
 
-internal fun String.indented(nSpaces: Int = 4): String {
+/**
+ * @param skipFirstLine if true doesn't indent first line
+ */
+internal fun String.indented(nSpaces: Int = 4, skipFirstLine: Boolean = false): String {
     val spaces = String(CharArray(nSpaces) { ' ' })
-    return lines().joinToString("\n") {
-        if (it.isNotBlank()) "$spaces$it" else it
-    }
+
+    return lines()
+        .withIndex()
+        .joinToString(separator = "\n") { (index, line) ->
+            if (skipFirstLine && index == 0) return@joinToString line
+            if (line.isNotBlank()) "$spaces$line" else line
+        }
 }
+
+internal val outputSourceRoot get() = System.getProperties()["org.jetbrains.kotlin.generators.gradle.dsl.outputSourceRoot"] as String

libraries/tools/kotlin-gradle-plugin-dsl-codegen/src/main/kotlin/org/jetbrains/kotlin/generators/gradle/dsl/kpmNativeVariantCodegen.kt

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+@file:OptIn(ExperimentalPathApi::class)
+
+package org.jetbrains.kotlin.generators.gradle.dsl
+
+import org.jetbrains.kotlin.konan.target.KonanTarget
+import org.jetbrains.kotlin.konan.target.presetName
+import kotlin.io.path.ExperimentalPathApi
+import kotlin.io.path.Path
+import kotlin.io.path.writeText
+
+fun main() {
+    generateKpmNativeVariantPresets()
+}
+
+fun generateKpmNativeVariantPresets() {
+    val sourceCode = kpmNativeVariantsSourceCode()
+    Path(outputSourceRoot)
+        .resolve(packageName.replace(".", "/"))
+        .resolve(fileName)
+        .writeText(sourceCode)
+}
+
+fun kpmNativeVariantsSourceCode() = """
+    package $packageName
+
+    import org.gradle.api.artifacts.Configuration
+    import org.jetbrains.kotlin.konan.target.KonanTarget
+    import javax.inject.Inject
+
+    // DO NOT EDIT MANUALLY! Generated by ${object {}.javaClass.enclosingClass.name}
+    ${variantClasses().indented(skipFirstLine = true)}
+
+    ${allVariantConstructors().indented(skipFirstLine = true)}
+    
+    ${kpmVariantClassFunction().indented(skipFirstLine = true)}
+""".trimIndent()
+
+private val fileName = "KpmNativeVariants.kt"
+
+private val packageName = "org.jetbrains.kotlin.gradle.plugin.mpp.pm20"
+
+private fun allKonanTargets() = KonanTarget.predefinedTargets.values
+
+private fun variantClasses() = allKonanTargets()
+    .map { variantClass(it) }
+    .joinToString("\n\n")
+
+private fun variantClass(konanTarget: KonanTarget) = """
+    open class ${konanTarget.variantClassName} @Inject constructor(
+        containingModule: KotlinGradleModule,
+        fragmentName: String,
+        dependencyConfigurations: KotlinFragmentDependencyConfigurations,
+        compileDependencyConfiguration: Configuration,
+        apiElementsConfiguration: Configuration,
+        hostSpecificMetadataElementsConfiguration: Configuration?
+    ) : KotlinNativeVariantInternal(
+        containingModule = containingModule,
+        fragmentName = fragmentName,
+        konanTarget = KonanTarget.${konanTarget.className},
+        dependencyConfigurations = dependencyConfigurations,
+        compileDependencyConfiguration = compileDependencyConfiguration,
+        apiElementsConfiguration = apiElementsConfiguration,
+        hostSpecificMetadataElementsConfiguration = hostSpecificMetadataElementsConfiguration
+    ) {
+        companion object {
+            val constructor = KotlinNativeVariantConstructor(
+                KonanTarget.${konanTarget.className}, ${konanTarget.variantClassName}::class.java, ::${konanTarget.variantClassName}
+            )
+        }
+    }
+""".trimIndent()
+
+private fun kpmVariantClassFunction(): String {
+    val konanTargetToVariant  = allKonanTargets()
+        .joinToString("\n") { "KonanTarget.${it.className} -> ${it.variantClassName}::class.java" }
+
+    return """
+        internal fun kpmVariantClass(konanTarget: KonanTarget): Class<out KotlinNativeVariantInternal>? = when (konanTarget) {
+            ${konanTargetToVariant.indented(nSpaces = 12, skipFirstLine = true)}
+            else -> null
+        }
+    """.trimIndent()
+}
+
+private fun allVariantConstructors() = allKonanTargets()
+    .joinToString(
+        prefix = "internal val allKpmNativeVariantConstructors = listOf(\n",
+        separator = ",\n",
+        postfix = "\n)"
+    ) { "${it.variantClassName}.constructor".indented() }
+
+private val KonanTarget.variantClassName
+    get() = presetName
+        .capitalize()
+        .let { "Kotlin${it}Variant" }
+
+private val KonanTarget.className get() = javaClass.simpleName

libraries/tools/kotlin-gradle-plugin-dsl-codegen/src/main/kotlin/org/jetbrains/kotlin/generators/gradle/dsl/mppNativeBinaryDSLCodegen.kt

@@ -201,7 +201,6 @@ fun generateAbstractKotlinNativeBinaryContainer() {
         "}"
     ).joinToString(separator = "\n\n")
 
-    val outputSourceRoot = System.getProperties()["org.jetbrains.kotlin.generators.gradle.dsl.outputSourceRoot"]
     val targetFile = File("$outputSourceRoot/${className.fqName.replace(".", "/")}.kt")
     targetFile.writeText(code)
 }

libraries/tools/kotlin-gradle-plugin-dsl-codegen/src/main/kotlin/org/jetbrains/kotlin/generators/gradle/dsl/mppPresetFunctionsCodegen.kt

@@ -53,7 +53,6 @@ private fun generateKotlinTargetContainerWithPresetFunctionsInterface() {
         "}"
     ).joinToString("\n\n")
 
-    val outputSourceRoot = System.getProperties()["org.jetbrains.kotlin.generators.gradle.dsl.outputSourceRoot"]
     val targetFile = File("$outputSourceRoot/${className.fqName.replace(".", "/")}.kt")
     targetFile.writeText(code)
 }