Register KotlinModelBuilder for kotlin-android plugin

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/model/KotlinProjectIT.kt

@@ -7,14 +7,23 @@ package org.jetbrains.kotlin.gradle.model
 
 import org.jetbrains.kotlin.gradle.BaseGradleIT
 import org.jetbrains.kotlin.gradle.GradleVersionRequired
+import org.jetbrains.kotlin.test.KotlinTestUtils
 import org.junit.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
+import kotlin.test.assertNotEquals
 import kotlin.test.assertTrue
 
 class KotlinProjectIT : BaseGradleIT() {
     override val defaultGradleVersion: GradleVersionRequired
-        get() = GradleVersionRequired.AtLeast("4.0")
+        get() = GradleVersionRequired.AtLeast("4.1")
+
+    override fun defaultBuildOptions(): BuildOptions {
+        return super.defaultBuildOptions().copy(
+            androidGradlePluginVersion = "3.0.0",
+            androidHome = KotlinTestUtils.findAndroidSdk()
+        )
+    }
 
     @Test
     fun testKotlinProject() {
@@ -25,7 +34,8 @@ class KotlinProjectIT : BaseGradleIT() {
             "kotlinProject",
             defaultBuildOptions().kotlinVersion,
             KotlinProject.ProjectType.PLATFORM_JVM,
-            "DEFAULT")
+            "DEFAULT"
+        )
         assertTrue(kotlinProject.expectedByDependencies.isEmpty())
 
         assertEquals(2, kotlinProject.sourceSets.size)
@@ -120,6 +130,39 @@ class KotlinProjectIT : BaseGradleIT() {
         assertEquals(project.projectDir.resolve("libJs/build/resources/test"), testJsSourceSet.resourcesOutputDirectory)
     }
 
+    @Test
+    fun testAndroidProject() {
+        val project = Project("AndroidExtensionsProject")
+        val kotlinProject = project.getModels(KotlinProject::class.java).getModel(":app")!!
+
+        kotlinProject.assertBasics(
+            "app",
+            defaultBuildOptions().kotlinVersion,
+            KotlinProject.ProjectType.PLATFORM_JVM,
+            "DEFAULT"
+        )
+
+        val expectedSourceSetNames = listOf("release", "debug", "releaseUnitTest", "debugUnitTest", "debugAndroidTest")
+        assertTrue(kotlinProject.expectedByDependencies.isEmpty())
+        assertEquals(5, kotlinProject.sourceSets.size)
+
+        fun verifySourceSet(sourceSet: SourceSet) {
+            // These are unused in Android projects so will be empty.
+            assertEquals(0, sourceSet.sourceDirectories.size)
+            assertEquals(0, sourceSet.resourcesDirectories.size)
+            assertEquals(project.projectDir.resolve("build/tmp/kotlin-classes/${sourceSet.name}"), sourceSet.classesOutputDirectory)
+            // This value is just a placeholder since this information is obtained from the Android Plugin models.
+            assertEquals(project.projectDir.resolve("build/tmp/kotlin-classes/${sourceSet.name}"), sourceSet.resourcesOutputDirectory)
+            assertNotEquals(0, sourceSet.compilerArguments.currentArguments.size)
+            assertNotEquals(0, sourceSet.compilerArguments.defaultArguments.size)
+        }
+
+        assertEquals(0, kotlinProject.sourceSets.filter {
+            verifySourceSet(it)
+            expectedSourceSetNames.contains(it.name)
+        }.size)
+    }
+
     @Test
     fun testCoroutinesProjectDSL() {
         val project = Project("coroutinesProjectDSL")

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/model/builder/KotlinModelBuilder.kt

@@ -26,7 +26,7 @@ import org.jetbrains.kotlin.gradle.tasks.AbstractKotlinCompile
 
 /**
  * [ToolingModelBuilder] for [KotlinProject] models.
- * This model builder is registered for base Kotlin JVM, Kotlin JS and Kotlin Common plugins.
+ * This model builder is registered for base Kotlin JVM (including Android), Kotlin JS and Kotlin Common plugins.
  */
 class KotlinModelBuilder(private val kotlinPluginVersion: String) : ToolingModelBuilder {
 
@@ -42,7 +42,9 @@ class KotlinModelBuilder(private val kotlinPluginVersion: String) : ToolingModel
                 project.name,
                 kotlinPluginVersion,
                 projectType,
-                kotlinCompileTasks.mapNotNull { it.createSourceSet(project, projectType) },
+                kotlinCompileTasks.mapNotNull {
+                    if (project.isAndroid()) it.createAndroidSourceSet() else it.createSourceSet(project, projectType)
+                },
                 getExpectedByDependencies(project),
                 kotlinCompileTasks.first()!!.createExperimentalFeatures()
             )
@@ -51,9 +53,14 @@ class KotlinModelBuilder(private val kotlinPluginVersion: String) : ToolingModel
     }
 
     companion object {
+        private fun Project.isAndroid(): Boolean {
+            return project.plugins.hasPlugin("kotlin-android")
+        }
 
         private fun getProjectType(project: Project): KotlinProject.ProjectType {
-            return if (project.plugins.hasPlugin("kotlin") || project.plugins.hasPlugin("kotlin-platform-jvm")) {
+            return if (project.plugins.hasPlugin("kotlin") || project.plugins.hasPlugin("kotlin-platform-jvm") ||
+                project.isAndroid()
+            ) {
                 KotlinProject.ProjectType.PLATFORM_JVM
             } else if (project.plugins.hasPlugin("kotlin2js") || project.plugins.hasPlugin("kotlin-platform-js")) {
                 KotlinProject.ProjectType.PLATFORM_JS
@@ -91,6 +98,24 @@ class KotlinModelBuilder(private val kotlinPluginVersion: String) : ToolingModel
             } else null
         }
 
+        /**
+         * The [SourceSet] returned by this method is not intended to be complete, most of the information here is exposed by the
+         * Android Gradle plugin and as such is not populated here. The important information here that is required by
+         * Android Studio are the [CompilerArguments].
+         */
+        private fun AbstractKotlinCompile<*>.createAndroidSourceSet(): SourceSet {
+            return SourceSetImpl(
+                sourceSetName,
+                if (sourceSetName.contains("test", true)) SourceSet.SourceSetType.TEST else SourceSet.SourceSetType.PRODUCTION,
+                findFriendSourceSets(),
+                emptyList(), // Obtained from the Android model
+                emptyList(), // Obtained from the Android model
+                destinationDir,
+                destinationDir, // Obtained from the Android model
+                createCompilerArguments()
+            )
+        }
+
         private fun AbstractKotlinCompile<*>.findFriendSourceSets(): Collection<String> {
             val friendSourceSets = ArrayList<String>()
             friendTask?.sourceSetName?.let { friendSourceSets.add(it) }

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

@@ -559,7 +559,8 @@ internal open class Kotlin2JsPlugin(
 }
 
 internal open class KotlinAndroidPlugin(
-    private val kotlinPluginVersion: String
+    private val kotlinPluginVersion: String,
+    private val registry: ToolingModelBuilderRegistry
 ) : Plugin<Project> {
 
     override fun apply(project: Project) {
@@ -570,6 +571,7 @@ internal open class KotlinAndroidPlugin(
             project, androidTarget, tasksProvider,
             kotlinPluginVersion
         )
+        registry.register(KotlinModelBuilder(kotlinPluginVersion))
     }
 
     companion object {
@@ -733,7 +735,7 @@ abstract class AbstractAndroidProjectHandler<V>(private val kotlinConfigurationT
         kotlinTask.destinationDir = File(project.buildDir, "tmp/kotlin-classes/$variantDataName")
         kotlinTask.description = "Compiles the $variantDataName kotlin."
 
-        // Register the source only after the task is created, because tne task is required for that:
+        // Register the source only after the task is created, because the task is required for that:
         compilation.source(defaultSourceSet)
         configureSources(kotlinTask, variantData, compilation)
 

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

@@ -116,7 +116,7 @@ open class KotlinAndroidPluginWrapper @Inject constructor(
     protected val registry: ToolingModelBuilderRegistry
 ) : KotlinBasePluginWrapper(fileResolver) {
     override fun getPlugin(project: Project, kotlinGradleBuildServices: KotlinGradleBuildServices): Plugin<Project> =
-        KotlinAndroidPlugin(kotlinPluginVersion)
+        KotlinAndroidPlugin(kotlinPluginVersion, registry)
 }
 
 open class Kotlin2JsPluginWrapper @Inject constructor(