Decouple Kapt task from KotlinCompile task configuration

This fixes KotlinCompile task instantiation on configuring Kapt tasks
as well Kapt tasks itself eager realization.

Additionally this change removes circular dependency between kapt and
compilation tasks.

^KT-54468 In Progress

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

@@ -27,8 +27,7 @@ class ConfigurationAvoidanceIT : KGPBaseTest() {
 
     @JvmGradlePluginTests
     @GradleTestVersions(
-        maxVersion = TestVersions.Gradle.G_7_5,
-        additionalVersions = [TestVersions.Gradle.G_7_3, TestVersions.Gradle.G_7_4]
+        additionalVersions = [TestVersions.Gradle.G_7_3]
     )
     @DisplayName("KGP/Jvm does not eagerly configure any tasks")
     @GradleTest
@@ -49,6 +48,29 @@ class ConfigurationAvoidanceIT : KGPBaseTest() {
         }
     }
 
+    @OtherGradlePluginTests
+    @GradleTestVersions(
+        additionalVersions = [TestVersions.Gradle.G_7_3]
+    )
+    @DisplayName("KGP/Kapt does not eagerly configure any tasks")
+    @GradleTest
+    fun testKaptConfigurationAvoidance(gradleVersion: GradleVersion) {
+        project("kapt2/simple", gradleVersion) {
+            buildGradle.appendText(
+                """
+                |
+                |tasks.configureEach {
+                |    if (name != "help" && name != "clean") {
+                |        throw new GradleException("Configuration avoidance failure for ${'$'}name!")
+                |    }
+                |}
+                """.trimMargin()
+            )
+
+            build("--dry-run")
+        }
+    }
+
     @AndroidGradlePluginTests
     @DisplayName("Android unrelated tasks are not configured")
     @AndroidTestVersions(minVersion = TestVersions.AGP.AGP_42)

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/simple/build.gradle

@@ -1,3 +1,5 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
+
 plugins {
     id "java"
     id "org.jetbrains.kotlin.jvm"
@@ -16,4 +18,6 @@ dependencies {
     testImplementation 'junit:junit:4.13.2'
 }
 
-compileKotlin.kotlinOptions.allWarningsAsErrors = true
+tasks.named("compileKotlin", KotlinJvmCompile) {
+    compilerOptions.allWarningsAsErrors = true
+}

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

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.gradle.internal.Kapt3GradleSubplugin.Companion.isUse
 import org.jetbrains.kotlin.gradle.model.builder.KaptModelBuilder
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinWithJavaCompilation
 import org.jetbrains.kotlin.gradle.tasks.*
 import org.jetbrains.kotlin.gradle.tasks.configuration.*
 import org.jetbrains.kotlin.gradle.utils.SingleWarningPerBuild
@@ -283,15 +284,12 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
         )
 
         val kaptGenerateStubsTaskProvider: TaskProvider<KaptGenerateStubsTask> = context.createKaptGenerateStubsTask()
-        val kaptTaskProvider: TaskProvider<out KaptTask> = context.createKaptKotlinTask()
+        val kaptTaskProvider: TaskProvider<out KaptTask> = context.createKaptKotlinTask(
+            kaptGenerateStubsTaskProvider
+        )
 
         kaptGenerateStubsTaskProvider.configure { kaptGenerateStubsTask ->
             kaptGenerateStubsTask.dependsOn(*buildDependencies.toTypedArray())
-            kaptGenerateStubsTask.dependsOn(
-                project.provider {
-                    kotlinCompilation.compileKotlinTask.dependsOn.filter { it !is TaskProvider<*> || it.name != kaptTaskProvider.name }
-                }
-            )
 
             if (androidVariantData != null) {
                 kaptGenerateStubsTask.additionalSources.from(
@@ -305,9 +303,6 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
             }
         }
 
-        kaptTaskProvider.configure { kaptTask ->
-            kaptTask.dependsOn(kaptGenerateStubsTaskProvider)
-        }
         context.kotlinCompile.configure { it.dependsOn(kaptTaskProvider) }
 
         /** Plugin options are applied to kapt*Compile inside [createKaptKotlinTask] */
@@ -357,9 +352,16 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
         ).get()
     }
 
-    private fun Kapt3SubpluginContext.createKaptKotlinTask(): TaskProvider<out KaptTask> {
+    private fun Kapt3SubpluginContext.createKaptKotlinTask(
+        generateStubsTask: TaskProvider<KaptGenerateStubsTask>
+    ): TaskProvider<out KaptTask> {
         val taskName = getKaptTaskName("kapt")
-        val taskConfigAction = KaptWithoutKotlincConfig(kotlinCompilation.compileKotlinTaskProvider.get() as KotlinCompile, kaptExtension)
+        @Suppress("UNCHECKED_CAST")
+        val taskConfigAction = KaptWithoutKotlincConfig(
+            kotlinCompilation.project,
+            generateStubsTask,
+            kaptExtension
+        )
 
         val kaptClasspathConfiguration = project.configurations.create("kaptClasspath_$taskName")
             .setExtendsFrom(kaptClasspathConfigurations).also {
@@ -367,6 +369,8 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
                 it.isCanBeConsumed = false
             }
         taskConfigAction.configureTaskProvider { taskProvider ->
+            taskProvider.dependsOn(generateStubsTask)
+
             if (javaCompile != null) {
                 val androidVariantData = KaptWithAndroid.androidVariantData(this)
                 if (androidVariantData != null) {
@@ -379,7 +383,14 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
                 disableAnnotationProcessingInJavaTask()
             }
 
-            kotlinCompilation.output.classesDirs.from(taskProvider.flatMap { it.classesDir })
+            // Workaround for changes in Gradle 7.3 causing eager task realization
+            // For details check `KotlinSourceSetProcessor.prepareKotlinCompileTask()`
+            if (kotlinCompilation is KotlinWithJavaCompilation<*, *>) {
+                val kotlinSourceDirectorySet = kotlinCompilation.defaultSourceSet.kotlin
+                kotlinSourceDirectorySet.compiledBy(taskProvider, KaptTask::classesDir)
+            } else {
+                kotlinCompilation.output.classesDirs.from(taskProvider.flatMap { it.classesDir })
+            }
 
             kotlinCompilation.compileTaskProvider.configure { task ->
                 with(task as AbstractKotlinCompile<*>) {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/configuration/KaptConfig.kt

@@ -24,12 +24,10 @@ import org.jetbrains.kotlin.gradle.internal.kapt.incremental.CLASS_STRUCTURE_ART
 import org.jetbrains.kotlin.gradle.internal.kapt.incremental.StructureTransformAction
 import org.jetbrains.kotlin.gradle.internal.kapt.incremental.StructureTransformLegacyAction
 import org.jetbrains.kotlin.gradle.plugin.*
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import org.jetbrains.kotlin.gradle.tasks.toCompilerPluginOptions
 import org.jetbrains.kotlin.gradle.utils.listProperty
 import org.jetbrains.kotlin.gradle.utils.markResolvable
 import java.io.File
-import java.util.concurrent.Callable
 
 internal open class KaptConfig<TASK : KaptTask>(
     project: Project,
@@ -49,7 +47,7 @@ internal open class KaptConfig<TASK : KaptTask>(
                 task.includeCompileClasspath.set(ext.includeCompileClasspath ?: project.isIncludeCompileClasspath())
                 task.classpathStructure.from(kaptClasspathSnapshot)
 
-                task.localStateDirectories.from(Callable { task.incAptCache.orNull })
+                task.localStateDirectories.from({ task.incAptCache.orNull })
                 task.onlyIf {
                     it as KaptTask
                     it.includeCompileClasspath.get() || !it.kaptClasspath.isEmpty
@@ -58,18 +56,26 @@ internal open class KaptConfig<TASK : KaptTask>(
         }
     }
 
-    internal constructor(kotlinCompileTask: KotlinCompile, ext: KaptExtension) : this(kotlinCompileTask.project, ext) {
+    internal constructor(
+        project: Project,
+        kaptGenerateStubsTask: TaskProvider<KaptGenerateStubsTask>,
+        ext: KaptExtension
+    ) : this(project, ext) {
         configureTask { task ->
-            task.classpath.from(kotlinCompileTask.libraries - project.files(task.classesDir))
-            task.compiledSources.from(
-                kotlinCompileTask.destinationDirectory,
-                Callable { kotlinCompileTask.javaOutputDir.takeIf { it.isPresent } })
+            task.classpath.from(
+                kaptGenerateStubsTask.map { it.libraries }
+            )
+            task.compiledSources
+                .from(
+                    kaptGenerateStubsTask.flatMap { it.kotlinCompileDestinationDirectory },
+                    { kaptGenerateStubsTask.get().javaOutputDir.takeIf { it.isPresent } }
+                )
                 .disallowChanges()
-            task.sourceSetName.value(kotlinCompileTask.sourceSetName).disallowChanges()
+            task.sourceSetName.value(kaptGenerateStubsTask.flatMap { it.sourceSetName }).disallowChanges()
 
 
             val kaptSources = objectFactory.fileCollection()
-                .from(kotlinCompileTask.javaSources, task.stubsDir)
+                .from(kaptGenerateStubsTask.map { it.javaSources }, task.stubsDir)
                 .asFileTree
                 .matching { it.include("**/*.java") }
                 .filter {
@@ -175,14 +181,21 @@ internal class KaptWithoutKotlincConfig : KaptConfig<KaptWithoutKotlincTask> {
             )
             task.kaptJars.from(project.configurations.getByName(Kapt3GradleSubplugin.KAPT_WORKER_DEPENDENCIES_CONFIGURATION_NAME))
             task.mapDiagnosticLocations = ext.mapDiagnosticLocations
-            task.annotationProcessorFqNames.set(providers.provider { ext.processors.split(',').filter { it.isNotEmpty() } })
+            task.annotationProcessorFqNames.set(providers.provider {
+                @Suppress("DEPRECATION")
+                ext.processors.split(',').filter { it.isNotEmpty() }
+            })
             task.disableClassloaderCacheForProcessors = project.disableClassloaderCacheForProcessors()
             task.classLoadersCacheSize = project.classLoadersCacheSize()
             task.javacOptions.set(getJavaOptions(task.defaultJavaSourceCompatibility))
         }
     }
 
-    constructor(kotlinCompileTask: KotlinCompile, ext: KaptExtension) : super(kotlinCompileTask, ext) {
+    constructor(
+        project: Project,
+        kaptGenerateStubsTask: TaskProvider<KaptGenerateStubsTask>,
+        ext: KaptExtension
+    ) : super(project, kaptGenerateStubsTask, ext) {
         project.configurations.findByName(Kapt3GradleSubplugin.KAPT_WORKER_DEPENDENCIES_CONFIGURATION_NAME)
             ?: project.configurations.create(Kapt3GradleSubplugin.KAPT_WORKER_DEPENDENCIES_CONFIGURATION_NAME).apply {
                 dependencies.addAllLater(project.listProperty {