Move Android Extensions subplugin to the main kotlin-gradle-plugin artifact

libraries/examples/kotlin-gradle-subplugin-example/src/main/kotlin/example/ExampleSubplugin.kt

@@ -23,7 +23,11 @@ import org.jetbrains.kotlin.gradle.plugin.SubpluginOption
 
 public class ExampleSubplugin : KotlinGradleSubplugin {
 
-    override fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption>? {
+    override fun isApplicable(project: Project, task: AbstractCompile): Boolean {
+        return true
+    }
+
+    override fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption> {
         println("ExampleSubplugin loaded")
         return listOf(SubpluginOption("exampleKey", "exampleValue"))
     }

libraries/tools/kotlin-android-extensions/pom.xml

@@ -21,49 +21,7 @@
 
     <description>Android compiler plugin for Kotlin</description>
 
-    <dependencies>
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>kotlin-stdlib</artifactId>
-            <version>${project.version}</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>kotlin-gradle-plugin</artifactId>
-            <version>${project.version}</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>kotlin-gradle-plugin-api</artifactId>
-            <version>${project.version}</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>gradle-api</artifactId>
-            <version>2.2</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.android.tools.build</groupId>
-            <artifactId>gradle</artifactId>
-            <version>1.1.0</version>
-            <scope>provided</scope>
-        </dependency>
-    </dependencies>
-
     <build>
-        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
-
-        <resources>
-            <resource>
-                <directory>${project.basedir}/src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-
         <plugins>
             <plugin>
                 <artifactId>kotlin-maven-plugin</artifactId>

libraries/tools/kotlin-android-extensions/src/main/resources/META-INF/services/org.jetbrains.kotlin.gradle.plugin.KotlinGradleSubplugin

@@ -1 +0,0 @@
-org.jetbrains.kotlin.android.AndroidSubplugin

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

@@ -22,7 +22,8 @@ import org.gradle.api.tasks.compile.AbstractCompile
 public class SubpluginOption(val key: String, val value: String)
 
 public interface KotlinGradleSubplugin {
-    public fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption>?
+    public fun isApplicable(project: Project, task: AbstractCompile): Boolean
+    public fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption>
     public fun getPluginName(): String
     public fun getGroupName(): String
     public fun getArtifactName(): String

libraries/tools/kotlin-gradle-plugin/pom.xml

@@ -25,6 +25,11 @@
           <artifactId>kotlin-stdlib</artifactId>
           <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-android-extensions</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.android.tools.build</groupId>
             <artifactId>gradle</artifactId>

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2014 JetBrains s.r.o.
+ * Copyright 2010-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,10 +14,11 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.android
+package org.jetbrains.kotlin.gradle.internal
 
 import com.android.build.gradle.BaseExtension
 import com.android.build.gradle.api.AndroidSourceSet
+import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.tasks.compile.AbstractCompile
 import org.jetbrains.kotlin.gradle.plugin.KotlinGradleSubplugin
@@ -27,11 +28,33 @@ import org.w3c.dom.Document
 import java.io.File
 import javax.xml.parsers.DocumentBuilderFactory
 
+// Use apply plugin: 'kotlin-android-extensions' to enable Android Extensions in an Android project.
+// Just a marker plugin.
+public class AndroidExtensionsSubpluginIndicator : Plugin<Project> {
+    override fun apply(target: Project?) {}
+}
+
 public class AndroidSubplugin : KotlinGradleSubplugin {
+    private companion object {
+        @Volatile
+        var migrateWarningReported: Boolean = false
+    }
 
-    override fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption>? {
-        val androidExtension = project.extensions.getByName("android") as? BaseExtension ?: return null
+    override fun isApplicable(project: Project, task: AbstractCompile): Boolean {
+        project.extensions.getByName("android") as? BaseExtension ?: return false
+        if (project.plugins.findPlugin(AndroidExtensionsSubpluginIndicator::class.java) == null) {
+            val dependencies = project.buildscript.configurations.getByName("classpath").dependencies
+            if (dependencies.any { it.name == getArtifactName() && it.group == getGroupName() } && !migrateWarningReported) {
+                project.logger.warn("To enable Android Extensions, use: \"apply plugin: 'kotlin-android-extensions'\"")
+                migrateWarningReported = true
+            }
+            return false
+        }
+        return true
+    }
 
+    override fun getExtraArguments(project: Project, task: AbstractCompile): List<SubpluginOption> {
+        val androidExtension = project.extensions.getByName("android") as? BaseExtension ?: return emptyList()
         val sourceSets = androidExtension.sourceSets
 
         val pluginOptions = arrayListOf<SubpluginOption>()

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

@@ -455,19 +455,21 @@ open class KotlinAndroidPlugin @Inject constructor(val scriptHandler: ScriptHand
 
 private fun loadSubplugins(project: Project): SubpluginEnvironment {
     try {
-        val subplugins = ServiceLoader.load(
-                KotlinGradleSubplugin::class.java, project.buildscript.classLoader).toList()
-        val subpluginDependencyNames =
-            subplugins.mapTo(hashSetOf<String>()) { it.getGroupName() + ":" + it.getArtifactName() }
+        val subplugins = ServiceLoader.load(KotlinGradleSubplugin::class.java, project.buildscript.classLoader).toList()
 
         val classpath = project.buildscript.configurations.getByName("classpath")
-        val subpluginClasspaths = hashMapOf<KotlinGradleSubplugin, List<String>>()
+        val resolvedClasspathArtifacts = classpath.resolvedConfiguration.resolvedArtifacts.toList()
+        val subpluginClasspaths = hashMapOf<KotlinGradleSubplugin, List<File>>()
 
         for (subplugin in subplugins) {
-            val files = classpath.dependencies
-                    .filter { subpluginDependencyNames.contains(it.group + ":" + it.name) }
-                    .flatMap { classpath.files(it).map { it.absolutePath } }
-            subpluginClasspaths.put(subplugin, files)
+            val file = resolvedClasspathArtifacts
+                    .firstOrNull {
+                        val id = it.moduleVersion.id
+                        subplugin.getGroupName() == id.group && subplugin.getArtifactName() == id.name
+                    }?.file
+            if (file != null) {
+                subpluginClasspaths.put(subplugin, listOf(file))
+            }
         }
 
         return SubpluginEnvironment(subpluginClasspaths, subplugins)
@@ -479,7 +481,7 @@ private fun loadSubplugins(project: Project): SubpluginEnvironment {
 }
 
 class SubpluginEnvironment(
-    val subpluginClasspaths: Map<KotlinGradleSubplugin, List<String>>,
+    val subpluginClasspaths: Map<KotlinGradleSubplugin, List<File>>,
     val subplugins: List<KotlinGradleSubplugin>
 ) {
 
@@ -488,17 +490,18 @@ class SubpluginEnvironment(
         val pluginArguments = arrayListOf<String>()
         fun getPluginOptionString(pluginId: String, key: String, value: String) = "plugin:$pluginId:$key=$value"
 
-        subplugins.forEach { subplugin ->
-            val args = subplugin.getExtraArguments(project, compileTask)
+        for (subplugin in subplugins) {
+            if (!subplugin.isApplicable(project, compileTask)) continue
 
             with (subplugin) {
                 project.logger.kotlinDebug("Subplugin ${getPluginName()} (${getGroupName()}:${getArtifactName()}) loaded.")
             }
 
             val subpluginClasspath = subpluginClasspaths[subplugin]
-            if (args != null && subpluginClasspath != null) {
-                realPluginClasspaths.addAll(subpluginClasspath)
-                for (arg in args) {
+            if (subpluginClasspath != null) {
+                subpluginClasspath.forEach { realPluginClasspaths.add(it.absolutePath) }
+
+                for (arg in subplugin.getExtraArguments(project, compileTask)) {
                     val option = getPluginOptionString(subplugin.getPluginName(), arg.key, arg.value)
                     pluginArguments.add(option)
                 }

libraries/tools/kotlin-gradle-plugin/src/main/resources/META-INF/gradle-plugins/kotlin-android-extensions.properties

@@ -0,0 +1 @@
+implementation-class=org.jetbrains.kotlin.gradle.internal.AndroidExtensionsSubpluginIndicator

libraries/tools/kotlin-gradle-plugin/src/main/resources/META-INF/services/org.jetbrains.kotlin.gradle.plugin.KotlinGradleSubplugin

@@ -0,0 +1 @@
+org.jetbrains.kotlin.gradle.internal.AndroidSubplugin