Apply scripting plugin in gradle plugin by default

libraries/tools/kotlin-gradle-plugin/build.gradle

@@ -51,6 +51,7 @@ dependencies {
             extension = 'jar'
         }
     }
+    compileOnly project(':kotlin-scripting-gradle')
 
     runtime project(path: ':kotlin-compiler-embeddable', configuration: "runtimeJar")
     runtime project(path: ':kotlin-annotation-processing-gradle', configuration: "runtimeJar")
@@ -60,6 +61,7 @@ dependencies {
     runtime project(':kotlin-scripting-common')
     runtime project(':kotlin-scripting-compiler')
     runtime project(':kotlin-scripting-jvm')
+    runtime project(path: ':kotlin-scripting-gradle', configuration: 'runtimeJar')
 
     // com.android.tools.build:gradle has ~50 unneeded transitive dependencies
     agp25CompileOnly('com.android.tools.build:gradle:3.0.0-alpha1') { transitive = false }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKa
 import org.jetbrains.kotlin.gradle.tasks.*
 import org.jetbrains.kotlin.gradle.utils.*
 import org.jetbrains.kotlin.incremental.configureMultiProjectIncrementalCompilation
+import org.jetbrains.kotlin.scripting.gradle.ScriptingGradleSubplugin
 import java.io.File
 import java.net.URL
 import java.util.*
@@ -427,6 +428,7 @@ internal open class KotlinPlugin(
 
     override fun apply(project: Project) {
         project.createKaptExtension()
+        project.pluginManager.apply(ScriptingGradleSubplugin::class.java)
         super.apply(project)
     }
 }

plugins/scripting/scripting-gradle/src/org/jetbrains/kotlin/scripting/gradle/ScriptingGradleSubplugin.kt

@@ -44,7 +44,8 @@ class ScriptingKotlinGradleSubplugin : KotlinGradleSubplugin<AbstractCompile> {
     ): List<SubpluginOption> {
         if (!ScriptingGradleSubplugin.isEnabled(project)) return emptyList()
 
-        val scriptingExtension = project.extensions.findByType(ScriptingExtension::class.java) ?: return emptyList()
+        val scriptingExtension = project.extensions.findByType(ScriptingExtension::class.java)
+                ?: project.extensions.create("kotlinScripting", ScriptingExtension::class.java)
 
         val options = mutableListOf<SubpluginOption>()