Add AP option providers of Android Gradle plugin as @Nested to Kapt

Also remove these option providers from the javac task compiler argument
providers so as to avoid output intersections of javac vs kapt.

The options generated by the providers are added to the Kapt subplugin
options as well in order to be passed to Kapt. Since these options
are a list, not a map, pass them without name (Kapt should decode them
into plain arguments). Remove the '-A' prefix as it is there for
command line annotation processor options, but we don't need it, it
is added by Kapt internally.

Issue #KT-23964 Fixed
Issue #KT-24420 Fixed

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

@@ -16,7 +16,68 @@ class KotlinAndroidGradleIT :
 class KotlinAndroidWithJackGradleIT : AbstractKotlinAndroidWithJackGradleTests(androidGradlePluginVersion = "2.3.+")
 
 // TODO If we there is a way to fetch the latest Android plugin version, test against the latest version
-class KotlinAndroid32GradleIT : KotlinAndroid3GradleIT(GradleVersionRequired.AtLeast("4.5"), "3.2.0-alpha06")
+class KotlinAndroid32GradleIT : KotlinAndroid3GradleIT(GradleVersionRequired.AtLeast("4.6"), "3.2.0-alpha15") {
+
+    @Test
+    fun testKaptUsingApOptionProvidersAsNestedInputOutput() = with(Project("AndroidProject", gradleVersion)) {
+        setupWorkingDir()
+
+        gradleBuildScript(subproject = "Android").appendText(
+            """
+
+            apply plugin: 'kotlin-kapt'
+
+            class MyNested implements org.gradle.process.CommandLineArgumentProvider {
+                String value = ""
+
+                @InputFile
+                File inputFile = null
+
+                @Override
+                Iterable<String> asArguments() { return [value] }
+            }
+
+            def nested = new MyNested()
+            nested.value = '123'
+            nested.inputFile = file("${'$'}projectDir/in.txt")
+
+            android.applicationVariants.all {
+                it.javaCompileOptions.annotationProcessorOptions.compilerArgumentProviders.add(nested)
+            }
+            """.trimIndent()
+        )
+
+        File(projectDir, "Android/in.txt").appendText("1234")
+
+        val kaptTasks = listOf(":Android:kaptFlavor1DebugKotlin")
+        val javacTasks = listOf(":Android:compileFlavor1DebugJavaWithJavac")
+
+        val buildTasks = (kaptTasks + javacTasks).toTypedArray()
+
+        build(*buildTasks) {
+            assertSuccessful()
+            assertTasksExecuted(kaptTasks + javacTasks)
+        }
+
+        File(projectDir, "Android/in.txt").appendText("5678")
+
+        build(*buildTasks) {
+            assertSuccessful()
+            assertTasksExecuted(kaptTasks)
+            assertTasksUpToDate(javacTasks)
+        }
+
+        gradleBuildScript(subproject = "Android").modify {
+            it.replace("nested.value = '123'", "nested.value = '456'")
+        }
+
+        build(*buildTasks) {
+            assertSuccessful()
+            assertTasksExecuted(kaptTasks)
+            assertTasksUpToDate(javacTasks)
+        }
+    }
+}
 
 class KotlinAndroid30GradleIT : KotlinAndroid3GradleIT(GradleVersionRequired.AtLeast("4.1"), "3.0.0")
 

libraries/tools/kotlin-gradle-plugin/src/agp25/kotlin/org/jetbrains/kotlin/gradle/plugin/android/Android25ProjectHandler.kt

@@ -128,6 +128,15 @@ class Android25ProjectHandler(kotlinConfigurationTools: KotlinConfigurationTools
             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

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

@@ -28,14 +28,16 @@ import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.TaskDependency
 import org.gradle.api.tasks.compile.AbstractCompile
 import org.gradle.api.tasks.compile.JavaCompile
+import org.gradle.process.CommandLineArgumentProvider
+import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedClassesDir
+import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedKotlinSourcesDir
+import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedSourcesDir
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.tasks.CompilerPluginOptions
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
-import java.io.File
-import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedSourcesDir
-import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedClassesDir
-import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.getKaptGeneratedKotlinSourcesDir
+import org.jetbrains.kotlin.gradle.utils.isGradleVersionAtLeast
 import java.io.ByteArrayOutputStream
+import java.io.File
 import java.io.ObjectOutputStream
 import java.util.*
 
@@ -69,6 +71,9 @@ abstract class KaptVariantData<T>(val variantData: T) {
             project: Project,
             kaptTask: KaptTask,
             javaTask: AbstractCompile)
+
+    open val annotationProcessorOptionProviders: List<*>
+        get() = emptyList<Any>()
 }
 
 // Subplugin for the Kotlin Gradle plugin
@@ -226,9 +231,20 @@ class Kapt3KotlinGradleSubplugin : KotlinGradleSubplugin<KotlinCompile> {
 
         kotlinSourcesOutputDir.mkdirs()
 
-        val apOptions =
-                (kaptExtension.getAdditionalArguments(project, kaptVariantData?.variantData, androidPlugin) + androidOptions)
-                        .map { SubpluginOption(it.key, it.value) } +
+        val apOptionsFromProviders =
+            if (isGradleVersionAtLeast(4, 6))
+                kaptVariantData?.annotationProcessorOptionProviders
+                    ?.flatMap { (it as CommandLineArgumentProvider).asArguments().map { "" to it.removePrefix("-A") } }
+                    .orEmpty()
+            else
+                emptyList()
+
+        val apOptionsPairsList: List<Pair<String, String>> =
+            kaptExtension.getAdditionalArguments(project, kaptVariantData?.variantData, androidPlugin).toList() +
+                    androidOptions.toList() +
+                    apOptionsFromProviders
+
+        val apOptions = apOptionsPairsList.map { SubpluginOption(it.first, it.second) } +
                 FilesSubpluginOption("kapt.kotlin.generated", listOf(kotlinSourcesOutputDir))
 
         pluginOptions += CompositeSubpluginOption("apoptions", encodeList(apOptions.associate { it.key to it.value }), apOptions)
@@ -312,13 +328,16 @@ class Kapt3KotlinGradleSubplugin : KotlinGradleSubplugin<KotlinCompile> {
 
         if (kaptVariantData != null) {
             kaptVariantData.registerGeneratedJavaSource(project, kaptTask, javaCompile)
-        }
-        else {
+        } else {
             registerGeneratedJavaSource(kaptTask, javaCompile)
         }
 
         kaptTask.kaptClasspathConfigurations = kaptClasspathConfigurations
 
+        kaptVariantData?.annotationProcessorOptionProviders?.let {
+            kaptTask.annotationProcessorOptionProviders.add(it)
+        }
+
         buildAndAddOptionsTo(kaptTask, kaptTask.pluginOptions, aptMode = "apt")
 
         return kaptTask
@@ -366,6 +385,15 @@ class Kapt3KotlinGradleSubplugin : KotlinGradleSubplugin<KotlinCompile> {
             newCompilerArgs.add("-proc:none")
             @Suppress("UNCHECKED_CAST")
             options.compilerArgs = newCompilerArgs as List<String>
+
+            if (isGradleVersionAtLeast(4, 6)) {
+                // Filter out the argument providers that are related to annotation processing and therefore already used by Kapt.
+                // This is done to avoid outputs intersections between Kapt and and javaCompile and make the up-to-date check for
+                // javaCompile more granular as it does not perform annotation processing:
+                if (kaptVariantData != null) {
+                    options.compilerArgumentProviders.removeAll(kaptVariantData.annotationProcessorOptionProviders)
+                }
+            }
         }
     }
 

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

@@ -56,6 +56,9 @@ open class KaptTask : ConventionTask(), CompilerArgumentAwareWithInput<K2JVMComp
     @get:OutputDirectory
     lateinit var kotlinSourcesDestinationDir: File
 
+    @get:Nested
+    internal val annotationProcessorOptionProviders: MutableList<Any> = mutableListOf()
+
     override fun createCompilerArgs(): K2JVMCompilerArguments = K2JVMCompilerArguments()
 
     override fun setupCompilerArgs(args: K2JVMCompilerArguments, defaultsOnly: Boolean) {