Refactor the Kotlin Android plugin to make it compliant with TCA

Also simplify some of the APIs and move some others which are only used
by kapt to the kapt's codebase.

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/Kapt3KotlinGradleSubplugin.kt

@@ -672,3 +672,22 @@ internal fun checkAndroidAnnotationProcessorDependencyUsage(project: Project) {
         )
     }
 }
+
+private val BaseVariant.annotationProcessorOptions: Map<String, String>?
+    get() = javaCompileOptions.annotationProcessorOptions.arguments
+
+private val BaseVariant.annotationProcessorOptionProviders: List<*>
+    get() = try {
+        // Public API added in Android Gradle Plugin 3.2.0-alpha15:
+        val apOptions = javaCompileOptions.annotationProcessorOptions
+        apOptions.javaClass.getMethod("getCompilerArgumentProviders").invoke(apOptions) as List<*>
+    } catch (e: NoSuchMethodException) {
+        emptyList<Any>()
+    }
+
+//TODO once the Android plugin reaches its 3.0.0 release, consider compiling against it (remove the reflective call)
+private val BaseVariant.dataBindingDependencyArtifactsIfSupported: FileCollection?
+    get() = this::class.java.methods
+        .find { it.name == "getDataBindingDependencyArtifacts" }
+        ?.also { it.isAccessible = true }
+        ?.invoke(this) as? FileCollection

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

@@ -744,15 +744,10 @@ class KotlinConfigurationTools internal constructor(
 abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTools: KotlinConfigurationTools) {
     protected val logger = Logging.getLogger(this.javaClass)
 
-    abstract fun getResDirectories(variantData: BaseVariant): FileCollection
     abstract fun getFlavorNames(variant: BaseVariant): List<String>
     abstract fun getBuildTypeName(variant: BaseVariant): String
     abstract fun getLibraryOutputTask(variant: BaseVariant): Any?
 
-    protected abstract fun getSourceProviders(variantData: BaseVariant): Iterable<SourceProvider>
-    protected abstract fun getJavaTask(variantData: BaseVariant): AbstractCompile?
-    protected abstract fun addJavaSourceDirectoryToVariantModel(variantData: BaseVariant, javaSourceDirectory: File): Unit
-
     protected open fun checkVariantIsValid(variant: BaseVariant) = Unit
 
     protected open fun setUpDependencyResolution(variant: BaseVariant, compilation: KotlinJvmAndroidCompilation) = Unit
@@ -763,12 +758,10 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
         androidPlugin: BasePlugin,
         androidExt: BaseExtension,
         variantData: BaseVariant,
-        javaTask: AbstractCompile,
+        javaTask: TaskProvider<out AbstractCompile>,
-        kotlinTask: KotlinCompile
+        kotlinTask: TaskProvider<out KotlinCompile>
     )
 
-    protected abstract fun wrapVariantDataForKapt(variantData: BaseVariant): KaptVariantData<BaseVariant>
-
     fun configureTarget(kotlinAndroidTarget: KotlinAndroidTarget) {
         val project = kotlinAndroidTarget.project
         val ext = project.extensions.getByName("android") as BaseExtension
@@ -903,8 +896,8 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
         if (kotlinAndroidTarget.disambiguationClassifier != null) {
 
             val sourceSetToVariants = mutableMapOf<AndroidSourceSet, MutableList<BaseVariant>>().apply {
-                project.forEachVariant { variant ->
+                forEachVariant(project) { variant ->
-                    for (sourceSet in getSourceProviders(variant)) {
+                    for (sourceSet in variant.sourceSets) {
                         val androidSourceSet = sourceSet as? AndroidSourceSet ?: continue
                         getOrPut(androidSourceSet) { mutableListOf() }.add(variant)
                     }
@@ -948,13 +941,6 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
         val variantDataName = getVariantName(variantData)
         logger.kotlinDebug("Process variant [$variantDataName]")
 
-        val javaTask = getJavaTask(variantData)
-
-        if (javaTask == null) {
-            logger.info("KOTLIN: javaTask is missing for $variantDataName, so Kotlin files won't be compiled for it")
-            return
-        }
-
         val defaultSourceSet = project.kotlinExtension.sourceSets.maybeCreate(compilation.defaultSourceSetName)
 
         val kotlinTaskName = compilation.compileKotlinTaskName
@@ -989,7 +975,7 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
         androidExt: BaseExtension,
         androidPlugin: BasePlugin
     ) {
-        val javaTask = getJavaTask(variantData) ?: return
+        val javaTask = variantData.getJavaTaskProvider()
 
         getTestedVariantData(variantData)?.let { testedVariant ->
             val testedVariantName = getVariantName(testedVariant)

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/Android25ProjectHandler.kt

@@ -7,24 +7,23 @@
 package org.jetbrains.kotlin.gradle.plugin
 
 import com.android.build.api.attributes.BuildTypeAttr
-import com.android.build.gradle.BaseExtension
+import com.android.build.gradle.*
-import com.android.build.gradle.BasePlugin
 import com.android.build.gradle.api.*
 import com.android.build.gradle.tasks.MergeResources
-import com.android.builder.model.SourceProvider
 import org.gradle.api.Project
 import org.gradle.api.artifacts.component.ProjectComponentIdentifier
 import org.gradle.api.attributes.Attribute
 import org.gradle.api.file.FileCollection
+import org.gradle.api.tasks.PathSensitivity
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.api.tasks.bundling.AbstractArchiveTask
 import org.gradle.api.tasks.compile.AbstractCompile
+import org.gradle.api.tasks.compile.JavaCompile
 import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin
-import org.jetbrains.kotlin.gradle.internal.KaptTask
-import org.jetbrains.kotlin.gradle.internal.KaptVariantData
 import org.jetbrains.kotlin.gradle.plugin.android.AndroidGradleWrapper
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.tasks.thisTaskProvider
 import org.jetbrains.kotlin.gradle.utils.addExtendsFromRelation
 import java.io.File
 import java.util.concurrent.Callable
@@ -39,25 +38,30 @@ class Android25ProjectHandler(
         androidPlugin: BasePlugin,
         androidExt: BaseExtension,
         variantData: BaseVariant,
-        javaTask: AbstractCompile,
+        javaTask: TaskProvider<out AbstractCompile>,
-        kotlinTask: KotlinCompile
+        kotlinTask: TaskProvider<out KotlinCompile>
     ) {
-        val preJavaKotlinOutputFiles = mutableListOf<File>().apply {
+        val preJavaKotlinOutput = project.files(project.provider {
-            add(kotlinTask.destinationDir)
+            mutableListOf<File>().apply {
-            if (Kapt3GradleSubplugin.isEnabled(project)) {
+                add(kotlinTask.get().destinationDir)
-                // Add Kapt3 output as well, since there's no SyncOutputTask with the new API
+                if (Kapt3GradleSubplugin.isEnabled(project)) {
-                val kaptClasssesDir = Kapt3GradleSubplugin.getKaptGeneratedClassesDir(project, getVariantName(variantData))
+                    // Add Kapt3 output as well, since there's no SyncOutputTask with the new API
-                add(kaptClasssesDir)
+                    val kaptClasssesDir = Kapt3GradleSubplugin.getKaptGeneratedClassesDir(project, getVariantName(variantData))
+                    add(kaptClasssesDir)
+                }
             }
-        }
+        }).builtBy(kotlinTask)
-        val preJavaKotlinOutput = project.files(*preJavaKotlinOutputFiles.toTypedArray()).builtBy(kotlinTask)
 
         val preJavaClasspathKey = variantData.registerPreJavacGeneratedBytecode(preJavaKotlinOutput)
-        kotlinTask.dependsOn(variantData.getSourceFolders(SourceKind.JAVA))
+        kotlinTask.configure { kotlinTaskInstance ->
+            kotlinTaskInstance.inputs.files(variantData.getSourceFolders(SourceKind.JAVA)).withPathSensitivity(PathSensitivity.RELATIVE)
 
-        kotlinTask.mapClasspath {
+            kotlinTaskInstance.mapClasspath {
-            val kotlinClasspath = variantData.getCompileClasspath(preJavaClasspathKey)
+                val kotlinClasspath = variantData.getCompileClasspath(preJavaClasspathKey)
-            kotlinClasspath + project.files(AndroidGradleWrapper.getRuntimeJars(androidPlugin, androidExt))
+                kotlinClasspath + project.files(AndroidGradleWrapper.getRuntimeJars(androidPlugin, androidExt))
+            }
+
+            kotlinTaskInstance.javaOutputDir = javaTask.get().destinationDir
         }
 
         // Find the classpath entries that come from the tested variant and register them as the friend paths, lazily
@@ -78,46 +82,16 @@ class Android25ProjectHandler(
             )
         )
 
-        kotlinTask.javaOutputDir = javaTask.destinationDir
+        compilation.output.classesDirs.from(
-
+            kotlinTask.map { it.destinationDir },
-        compilation.output.classesDirs.run {
+            javaTask.map { it.destinationDir }
-            from(project.files(kotlinTask.taskData.destinationDir).builtBy(kotlinTask))
+        )
-            from(project.files(project.provider { javaTask.destinationDir }).builtBy(javaTask))
-        }
     }
 
-    override fun getSourceProviders(variantData: BaseVariant): Iterable<SourceProvider> =
-        variantData.sourceSets
-
     override fun getFlavorNames(variant: BaseVariant): List<String> = variant.productFlavors.map { it.name }
 
     override fun getBuildTypeName(variant: BaseVariant): String = variant.buildType.name
 
-    override fun getJavaTask(variantData: BaseVariant): AbstractCompile? {
-        @Suppress("DEPRECATION") // There is always a Java compile task -- the deprecation was for Jack
-        return variantData::class.java.methods.firstOrNull { it.name == "getJavaCompileProvider" }
-            ?.invoke(variantData)
-            ?.let { taskProvider ->
-                // org.gradle.api.tasks.TaskProvider is added in Gradle 4.8
-                taskProvider::class.java.methods.firstOrNull { it.name == "get" }?.invoke(taskProvider) as AbstractCompile?
-            } ?: variantData.javaCompile
-    }
-
-    override fun addJavaSourceDirectoryToVariantModel(variantData: BaseVariant, javaSourceDirectory: File) =
-        variantData.addJavaSourceFoldersToModel(javaSourceDirectory)
-
-    override fun getResDirectories(variantData: BaseVariant): FileCollection {
-        val getAllResourcesMethod =
-            variantData::class.java.methods.firstOrNull { it.name == "getAllRawAndroidResources" }
-        if (getAllResourcesMethod != null) {
-            val allResources = getAllResourcesMethod.invoke(variantData) as FileCollection
-            return allResources
-        }
-
-        val project = variantData.mergeResources.project
-        return project.files(Callable { variantData.mergeResources?.computeResourceSetList0() ?: emptyList() })
-    }
-
     // TODO the return type is actually `AbstractArchiveTask | TaskProvider<out AbstractArchiveTask>`;
     //      change the signature once the Android Gradle plugin versions that don't support task providers are dropped
     override fun getLibraryOutputTask(variant: BaseVariant): Any? {
@@ -170,71 +144,6 @@ class Android25ProjectHandler(
             project.configurations.findByName(outputConfigurationName)?.usesPlatformOf(compilation.target)
         }
     }
-
-    private inner class KaptVariant(variantData: BaseVariant) : KaptVariantData<BaseVariant>(variantData) {
-        override val name: String = getVariantName(variantData)
-        override val sourceProviders: Iterable<SourceProvider> = getSourceProviders(variantData)
-        override fun addJavaSourceFoldersToModel(generatedFilesDir: File) =
-            addJavaSourceDirectoryToVariantModel(variantData, generatedFilesDir)
-
-        override val annotationProcessorOptions: Map<String, String>? =
-            variantData.javaCompileOptions.annotationProcessorOptions.arguments
-
-        override fun registerGeneratedJavaSource(
-            project: Project,
-            kaptTask: KaptTask,
-            javaTask: AbstractCompile
-        ) {
-            val kaptSourceOutput = project.fileTree(kaptTask.destinationDir).builtBy(kaptTask)
-            kaptSourceOutput.include("**/*.java")
-            variantData.registerExternalAptJavaOutput(kaptSourceOutput)
-            variantData.dataBindingDependencyArtifactsIfSupported?.let { kaptTask.dependsOn(it) }
-        }
-
-        override val annotationProcessorOptionProviders: List<*>
-            get() = try {
-                // Public API added in Android Gradle Plugin 3.2.0-alpha15:
-                val apOptions = variantData.javaCompileOptions.annotationProcessorOptions
-                apOptions.javaClass.getMethod("getCompilerArgumentProviders").invoke(apOptions) as List<*>
-            } catch (e: NoSuchMethodException) {
-                emptyList<Any>()
-            }
-    }
-
-    //TODO A public API is expected for this purpose. Once it is available, use the public API
-    private fun MergeResources.computeResourceSetList0(): List<File>? {
-        val computeResourceSetListMethod = MergeResources::class.java.declaredMethods
-            .firstOrNull { it.name == "computeResourceSetList" && it.parameterCount == 0 } ?: return null
-
-        val oldIsAccessible = computeResourceSetListMethod.isAccessible
-        try {
-            computeResourceSetListMethod.isAccessible = true
-
-            val resourceSets = computeResourceSetListMethod.invoke(this) as? Iterable<*>
-
-            return resourceSets
-                ?.mapNotNull { resourceSet ->
-                    val getSourceFiles = resourceSet?.javaClass?.methods?.find { it.name == "getSourceFiles" && it.parameterCount == 0 }
-                    val files = getSourceFiles?.invoke(resourceSet)
-                    @Suppress("UNCHECKED_CAST")
-                    files as? Iterable<File>
-                }
-                ?.flatten()
-
-        } finally {
-            computeResourceSetListMethod.isAccessible = oldIsAccessible
-        }
-    }
-
-    //TODO once the Android plugin reaches its 3.0.0 release, consider compiling against it (remove the reflective call)
-    private val BaseVariant.dataBindingDependencyArtifactsIfSupported: FileCollection?
-        get() = this::class.java.methods
-            .find { it.name == "getDataBindingDependencyArtifacts" }
-            ?.also { it.isAccessible = true }
-            ?.invoke(this) as? FileCollection
-
-    override fun wrapVariantDataForKapt(variantData: BaseVariant): KaptVariantData<BaseVariant> =
-        KaptVariant(variantData)
 }
 
 internal fun getTestedVariantData(variantData: BaseVariant): BaseVariant? = when (variantData) {
@@ -244,3 +153,64 @@ internal fun getTestedVariantData(variantData: BaseVariant): BaseVariant? = when
 }
 
 internal fun getVariantName(variant: BaseVariant): String = variant.name
+
+@Suppress("UNCHECKED_CAST")
+internal fun BaseVariant.getJavaTaskProvider(): TaskProvider<out JavaCompile> =
+    this::class.java.methods.firstOrNull { it.name == "getJavaCompileProvider" }
+        ?.invoke(this) as? TaskProvider<JavaCompile>
+        ?: @Suppress("DEPRECATION") javaCompile.thisTaskProvider
+
+internal fun forEachVariant(project: Project, action: (BaseVariant) -> Unit) {
+    val androidExtension = project.extensions.getByName("android")
+    when (androidExtension) {
+        is AppExtension -> androidExtension.applicationVariants.all(action)
+        is LibraryExtension -> {
+            androidExtension.libraryVariants.all(action)
+            if (androidExtension is FeatureExtension) {
+                androidExtension.featureVariants.all(action)
+            }
+        }
+        is TestExtension -> androidExtension.applicationVariants.all(action)
+    }
+    if (androidExtension is TestedExtension) {
+        androidExtension.testVariants.all(action)
+        androidExtension.unitTestVariants.all(action)
+    }
+}
+
+internal fun BaseVariant.getResDirectories(): FileCollection {
+    val getAllResourcesMethod =
+        this::class.java.methods.firstOrNull { it.name == "getAllRawAndroidResources" }
+    if (getAllResourcesMethod != null) {
+        val allResources = getAllResourcesMethod.invoke(this) as FileCollection
+        return allResources
+    }
+
+    val project = mergeResources.project
+    return project.files(Callable { mergeResources?.computeResourceSetList0() ?: emptyList() })
+}
+
+//TODO A public API is expected for this purpose. Once it is available, use the public API
+private fun MergeResources.computeResourceSetList0(): List<File>? {
+    val computeResourceSetListMethod = MergeResources::class.java.declaredMethods
+        .firstOrNull { it.name == "computeResourceSetList" && it.parameterCount == 0 } ?: return null
+
+    val oldIsAccessible = computeResourceSetListMethod.isAccessible
+    try {
+        computeResourceSetListMethod.isAccessible = true
+
+        val resourceSets = computeResourceSetListMethod.invoke(this) as? Iterable<*>
+
+        return resourceSets
+            ?.mapNotNull { resourceSet ->
+                val getSourceFiles = resourceSet?.javaClass?.methods?.find { it.name == "getSourceFiles" && it.parameterCount == 0 }
+                val files = getSourceFiles?.invoke(resourceSet)
+                @Suppress("UNCHECKED_CAST")
+                files as? Iterable<File>
+            }
+            ?.flatten()
+
+    } finally {
+        computeResourceSetListMethod.isAccessible = oldIsAccessible
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/jvm/KotlinJvmAndroidCompilation.kt

@@ -21,7 +21,8 @@ import org.jetbrains.kotlin.gradle.plugin.getTestedVariantData
      name: String
  ) : AbstractKotlinCompilationToRunnableFiles<KotlinJvmOptions>(target, name) {
 
-     lateinit internal var androidVariant: BaseVariant
+     lateinit var androidVariant: BaseVariant
+         internal set
 
      override val compileKotlinTask: org.jetbrains.kotlin.gradle.tasks.KotlinCompile
          get() = super.compileKotlinTask as org.jetbrains.kotlin.gradle.tasks.KotlinCompile