Refactoring: extract properties for gradle task's properties access in plugin

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

@@ -32,7 +32,6 @@ fun Project.initKapt(
         javaTask: AbstractCompile,
         kaptManager: AnnotationProcessingManager,
         variantName: String,
-        kotlinOutputDir: File,
         kotlinOptions: Any?,
         subpluginEnvironment: SubpluginEnvironment,
         taskFactory: (suffix: String) -> AbstractCompile
@@ -41,8 +40,7 @@ fun Project.initKapt(
     val kotlinAfterJavaTask: AbstractCompile?
 
     if (kaptExtension.generateStubs) {
-        kotlinAfterJavaTask = createKotlinAfterJavaTask(javaTask, kotlinTask,
+        kotlinAfterJavaTask = createKotlinAfterJavaTask(javaTask, kotlinTask, kotlinOptions, taskFactory)
-                kotlinOutputDir, kotlinOptions, taskFactory)
 
         kotlinTask.logger.kotlinDebug("kapt: Using class file stubs")
 
@@ -89,12 +87,11 @@ fun Project.initKapt(
 private fun Project.createKotlinAfterJavaTask(
         javaTask: AbstractCompile,
         kotlinTask: AbstractCompile,
-        kotlinOutputDir: File,
         kotlinOptions: Any?,
         taskFactory: (suffix: String) -> AbstractCompile
 ): AbstractCompile {
     val kotlinAfterJavaTask = with (taskFactory(KOTLIN_AFTER_JAVA_TASK_SUFFIX)) {
-        setProperty("kotlinDestinationDir", kotlinOutputDir)
+        kotlinDestinationDir = kotlinTask.kotlinDestinationDir
         destinationDir = javaTask.destinationDir
         classpath = javaTask.classpath
         this

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

@@ -130,9 +130,7 @@ class Kotlin2JvmSourceSetProcessor(
     }
 
     override fun doTargetSpecificProcessing() {
-        // store kotlin classes in separate directory. They will serve as class-path to java compiler
+        kotlinTask.kotlinDestinationDir = File(project.buildDir, "kotlin-classes/$sourceSetName")
-        val kotlinDestinationDir = File(project.buildDir, "kotlin-classes/${sourceSetName}")
-        kotlinTask.setProperty("kotlinDestinationDir", kotlinDestinationDir)
 
         val javaTask = project.tasks.findByName(sourceSet.compileJavaTaskName) as AbstractCompile?
         if (javaTask != null) {
@@ -166,7 +164,7 @@ class Kotlin2JvmSourceSetProcessor(
                             aptConfiguration.resolve(), aptOutputDir, aptWorkingDir, tasksProvider.tasksLoader)
 
                     val kotlinAfterJavaTask = project.initKapt(kotlinTask, javaTask, kaptManager,
-                            sourceSetName, kotlinDestinationDir, null, subpluginEnvironment) {
+                            sourceSetName, null, subpluginEnvironment) {
                         createKotlinCompileTask(it)
                     }
 
@@ -200,7 +198,7 @@ class Kotlin2JsSourceSetProcessor(
     val build = project.tasks.findByName("build")
 
     val defaultKotlinDestinationDir = File(project.buildDir, "kotlin2js/${sourceSetName}")
-    private fun kotlinTaskDestinationDir(): File? = kotlinTask.property("kotlinDestinationDir") as File?
+    private fun kotlinTaskDestinationDir(): File? = kotlinTask.kotlinDestinationDir
     private fun kotlinJsDestinationDir(): File? = (kotlinTask.property("outputFile") as String).let { File(it) }.let { if (it.isDirectory) it else it.parentFile }
 
     private fun kotlinSourcePathsForSourceMap() = sourceSet.getAllSource()
@@ -211,7 +209,7 @@ class Kotlin2JsSourceSetProcessor(
     private fun shouldGenerateSourceMap() = kotlinTask.property("sourceMap")
 
     override fun doTargetSpecificProcessing() {
-        kotlinTask.setProperty("kotlinDestinationDir", defaultKotlinDestinationDir)
+        kotlinTask.kotlinDestinationDir = defaultKotlinDestinationDir
         build?.dependsOn(kotlinTaskName)
         clean?.dependsOn("clean" + kotlinTaskName.capitalize())
 
@@ -366,8 +364,7 @@ open class KotlinAndroidPlugin @Inject constructor(val scriptHandler: ScriptHand
             }
 
             // store kotlin classes in separate directory. They will serve as class-path to java compiler
-            val kotlinOutputDir = File(project.buildDir, "tmp/kotlin-classes/${variantDataName}")
+            kotlinTask.kotlinDestinationDir = File(project.buildDir, "tmp/kotlin-classes/$variantDataName")
-            kotlinTask.setProperty("kotlinDestinationDir", kotlinOutputDir)
             kotlinTask.destinationDir = javaTask.destinationDir
             kotlinTask.description = "Compiles the ${variantDataName} kotlin."
             kotlinTask.classpath = javaTask.classpath
@@ -413,7 +410,7 @@ open class KotlinAndroidPlugin @Inject constructor(val scriptHandler: ScriptHand
 
             kotlinTask.doFirst {
                 val androidRT = project.files(AndroidGradleWrapper.getRuntimeJars(androidPlugin, androidExt))
-                val fullClasspath = (javaTask.classpath + androidRT) - project.files(kotlinTask.property("kotlinDestinationDir"))
+                val fullClasspath = (javaTask.classpath + androidRT) - project.files(kotlinTask.kotlinDestinationDir)
                 (it as AbstractCompile).classpath = fullClasspath
 
                 for (task in project.getTasksByName(kotlinTaskName + KOTLIN_AFTER_JAVA_TASK_SUFFIX, false)) {
@@ -430,8 +427,7 @@ open class KotlinAndroidPlugin @Inject constructor(val scriptHandler: ScriptHand
 
                 kotlinTask.storeKaptAnnotationsFile(kaptManager)
 
-                project.initKapt(kotlinTask, javaTask, kaptManager, variantDataName,
+                project.initKapt(kotlinTask, javaTask, kaptManager, variantDataName, kotlinOptions, subpluginEnvironment) {
-                        kotlinOutputDir, kotlinOptions, subpluginEnvironment) {
                     tasksProvider.createKotlinJVMTask(project, kotlinTaskName + KOTLIN_AFTER_JAVA_TASK_SUFFIX)
                 }
             }
@@ -456,16 +452,15 @@ private fun setUpKotlinToJavaDependency(project: Project, kotlinTask: AbstractCo
     // Since we cannot update classpath statically, java not able to detect changes in the classpath after kotlin compiler.
     // Therefore this (probably inefficient since java cannot decide "uptodateness" by the list of changed class files, but told
     // explicitly being out of date whenever any kotlin files are compiled
-    if (kotlinTask.hasProperty("anyClassesCompiled")) {
+    if (kotlinTask.anyClassesCompiled != null) {
-        kotlinTask.property("anyClassesCompiled")?.let {
+        kotlinTask.anyClassesCompiled = false
-            kotlinTask.setProperty("anyClassesCompiled", false)
+
-            javaTask.outputs.upToDateWhen { task ->
+        javaTask.outputs.upToDateWhen { task ->
-                val kotlinClassesCompiled = kotlinTask.property("anyClassesCompiled") as? Boolean ?: false
+            val kotlinClassesCompiled = kotlinTask.anyClassesCompiled ?: false
-                if (kotlinClassesCompiled) {
+            if (kotlinClassesCompiled) {
-                    logger.info("Marking $task out of date, because kotlin classes are changed")
+                logger.info("Marking $task out of date, because kotlin classes are changed")
-                }
-                !kotlinClassesCompiled
             }
+            !kotlinClassesCompiled
         }
     }
 

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

@@ -0,0 +1,29 @@
+package org.jetbrains.kotlin.gradle.plugin
+
+import org.gradle.api.internal.AbstractTask
+import org.gradle.api.tasks.compile.AbstractCompile
+import java.io.File
+import kotlin.reflect.KProperty
+
+internal var AbstractTask.anyClassesCompiled: Boolean? by TaskPropertyDelegate("anyClassesCompiled")
+internal var AbstractTask.kotlinDestinationDir: File? by TaskPropertyDelegate("kotlinDestinationDir")
+
+inline
+internal fun <reified T : Any> TaskPropertyDelegate(propertyName: String) =
+        TaskPropertyDelegate(propertyName, T::class.java)
+
+internal class TaskPropertyDelegate<T : Any>(private val propertyName: String, private val klass: Class<T>) {
+    operator fun getValue(task: Any?, property: KProperty<*>): T? {
+        if (task !is AbstractCompile) throw IllegalStateException("TaskPropertyDelegate could extend only AbstractCompile")
+
+        if ( !task.hasProperty(propertyName)) return null
+
+        return task.property(propertyName)?.let { klass.cast(it) }
+    }
+
+    operator fun setValue(task: Any?, property: KProperty<*>, value: T?) {
+        if (task !is AbstractCompile) throw IllegalStateException("TaskPropertyDelegate could extend only AbstractCompile")
+
+        task.setProperty(propertyName, value)
+    }
+}