Backport much of master to 1.9.x; KotlinCompile type, osdetector, lazy buildDir

build.gradle

@@ -41,11 +41,7 @@ ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
 
 repositories {
     maven { url "https://plugins.gradle.org/m2/" }
-    maven { url "https://repo.gradle.org/gradle/libs-releases-local/" }
     google()
-    // Needed for resolving 'kotlinx-metadata-jvm'
-    // A transitive dependency of gradle Kotlin DSL
-    maven { url "https://kotlin.bintray.com/kotlinx/" }
 }
 
 configurations {
@@ -55,8 +51,9 @@ configurations {
 
 dependencies {
   compileOnly "com.android.tools.build:gradle:4.1.0"
+  compileOnly "org.jetbrains.kotlin.android:org.jetbrains.kotlin.android.gradle.plugin:1.7.22"
 
-  implementation 'com.google.gradle:osdetector-gradle-plugin:1.7.1'
+  implementation 'com.google.gradle:osdetector-gradle-plugin:1.7.3'
 
   testImplementation 'junit:junit:4.12'
   testImplementation('org.spockframework:spock-core:1.0-groovy-2.4') {

src/main/groovy/com/google/protobuf/gradle/ProtobufExtension.groovy

@@ -38,6 +38,7 @@ import org.gradle.api.Action
 import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
 import org.gradle.api.provider.Property
+import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.TaskCollection
 
 /**
@@ -54,14 +55,16 @@ abstract class ProtobufExtension {
   private final NamedDomainObjectContainer<ProtoSourceSet> sourceSets
 
   @PackageScope
-  final String defaultGeneratedFilesBaseDir
+  final Provider<String> defaultGeneratedFilesBaseDir
 
   public ProtobufExtension(final Project project) {
     this.project = project
     this.tasks = new GenerateProtoTaskCollection(project)
     this.tools = new ToolsLocator(project)
     this.taskConfigActions = []
-    this.defaultGeneratedFilesBaseDir = "${project.buildDir}/generated/source/proto"
+    this.defaultGeneratedFilesBaseDir = project.layout.buildDirectory.dir("generated/source/proto").map {
+      it.asFile.path
+    }
     this.generatedFilesBaseDirProperty.convention(defaultGeneratedFilesBaseDir)
     this.sourceSets = project.objects.domainObjectContainer(ProtoSourceSet) { String name ->
       new DefaultProtoSourceSet(name, project.objects)

src/main/groovy/com/google/protobuf/gradle/ProtobufPlugin.groovy

@@ -55,9 +55,9 @@ import org.gradle.api.internal.artifacts.ArtifactAttributes
 import org.gradle.api.plugins.AppliedPlugin
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.SourceSet
-import org.gradle.api.tasks.SourceTask
 import org.gradle.language.jvm.tasks.ProcessResources
 import org.gradle.util.GradleVersion
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 /**
  * The main class for the protobuf plugin.
@@ -349,7 +349,7 @@ class ProtobufPlugin implements Plugin<Project> {
         project.plugins.withId("org.jetbrains.kotlin.android") {
           project.afterEvaluate {
             String compileKotlinTaskName = Utils.getKotlinAndroidCompileTaskName(project, variant.name)
-            project.tasks.named(compileKotlinTaskName, SourceTask) { SourceTask task ->
+            project.tasks.named(compileKotlinTaskName, KotlinCompile) { KotlinCompile task ->
               task.dependsOn(generateProtoTask)
               task.source(generateProtoTask.get().outputSourceDirectories)
             }
@@ -374,20 +374,20 @@ class ProtobufPlugin implements Plugin<Project> {
     ) {
       String sourceSetName = protoSourceSet.name
       String taskName = 'generate' + Utils.getSourceSetSubstringForTaskNames(sourceSetName) + 'Proto'
-      String defaultGeneratedFilesBaseDir = protobufExtension.defaultGeneratedFilesBaseDir
+      Provider<String> defaultGeneratedFilesBaseDir = protobufExtension.defaultGeneratedFilesBaseDir
       Provider<String> generatedFilesBaseDirProvider = protobufExtension.generatedFilesBaseDirProperty
       Provider<GenerateProtoTask> task = project.tasks.register(taskName, GenerateProtoTask) {
         CopyActionFacade copyActionFacade = CopyActionFacade.Loader.create(it.project, it.objectFactory)
         it.description = "Compiles Proto source for '${sourceSetName}'".toString()
-        it.outputBaseDir = project.providers.provider {
-          "${defaultGeneratedFilesBaseDir}/${sourceSetName}".toString()
+        it.outputBaseDir = defaultGeneratedFilesBaseDir.map {
+          "${it}/${sourceSetName}".toString()
         }
         it.addSourceDirs(protoSourceSet.proto)
         it.addIncludeDir(protoSourceSet.proto.sourceDirectories)
         it.addIncludeDir(protoSourceSet.includeProtoDirs)
         it.doLast { task ->
           String generatedFilesBaseDir = generatedFilesBaseDirProvider.get()
-          if (generatedFilesBaseDir == defaultGeneratedFilesBaseDir) {
+          if (generatedFilesBaseDir == defaultGeneratedFilesBaseDir.get()) {
             return
           }
           // Purposefully don't wire this up to outputs, as it can be mixed with other files.

src/test/groovy/com/google/protobuf/gradle/ProtobufAndroidPluginKotlinTest.groovy

@@ -8,9 +8,9 @@ import spock.lang.Unroll
 
 @CompileDynamic
 class ProtobufAndroidPluginKotlinTest extends Specification {
-  private static final List<String> GRADLE_VERSION = ["5.6", "6.5.1", "7.4.2"]
-  private static final List<String> ANDROID_PLUGIN_VERSION = ["3.5.0", "4.1.0", "7.2.1"]
-  private static final List<String> KOTLIN_VERSION = ["1.3.20", "1.3.20", "1.3.40"]
+  private static final List<String> GRADLE_VERSION = ["5.6", "6.5.1", "7.4.2", "7.6"]
+  private static final List<String> ANDROID_PLUGIN_VERSION = ["3.5.0", "4.1.0", "7.2.1", "7.3.1"]
+  private static final List<String> KOTLIN_VERSION = ["1.3.20", "1.3.20", "1.3.40", "1.7.20"]
 
   /**
    * This test may take a significant amount of Gradle daemon Metaspace memory in some

src/test/groovy/com/google/protobuf/gradle/ProtobufJavaPluginTest.groovy

@@ -15,8 +15,8 @@ import spock.lang.Unroll
 @CompileDynamic
 class ProtobufJavaPluginTest extends Specification {
   // Current supported version is Gradle 5+.
-  private static final List<String> GRADLE_VERSIONS = ["5.6", "6.0", "6.7.1", "7.4.2"]
-  private static final List<String> KOTLIN_VERSIONS = ["1.3.20", "1.3.31", "1.3.40"]
+  private static final List<String> GRADLE_VERSIONS = ["5.6", "6.0", "6.7.1", "7.4.2", "7.6"]
+  private static final List<String> KOTLIN_VERSIONS = ["1.3.72", "1.4.32", "1.5.32", "1.6.21", "1.7.21"]
 
   void "testApplying java and com.google.protobuf adds corresponding task to project"() {
     given: "a basic project with java and com.google.protobuf"
@@ -69,6 +69,18 @@ class ProtobufJavaPluginTest extends Specification {
     assert project.tasks.extractMain2Proto instanceof ProtobufExtract
   }
 
+  void "test buildDir is late bound"() {
+    given: "a basic project with java and com.google.protobuf"
+    Project project = setupBasicProject()
+
+    when: "project evaluated"
+    project.evaluate()
+    project.buildDir = "expect-the-unexpected"
+
+    then: "generate tasks added"
+    assert project.tasks.generateProto.outputBaseDir.contains("/expect-the-unexpected/")
+  }
+
   @Unroll
   void "testProject should be successfully executed (java-only project) [gradle #gradleVersion]"() {
     given: "project from testProject"
@@ -196,7 +208,8 @@ class ProtobufJavaPluginTest extends Specification {
     ProtobufPluginTestHelper.verifyProjectDir(projectDir)
 
     where:
-    [gradleVersion, kotlinVersion] << [GRADLE_VERSIONS, KOTLIN_VERSIONS].combinations()
+    gradleVersion << GRADLE_VERSIONS
+    kotlinVersion << KOTLIN_VERSIONS
   }
 
   @Unroll
@@ -219,7 +232,8 @@ class ProtobufJavaPluginTest extends Specification {
     ProtobufPluginTestHelper.verifyProjectDir(projectDir)
 
     where:
-    [gradleVersion, kotlinVersion] << [GRADLE_VERSIONS, KOTLIN_VERSIONS].combinations()
+    gradleVersion << GRADLE_VERSIONS
+    kotlinVersion << KOTLIN_VERSIONS
   }
 
   @Unroll

src/test/groovy/com/google/protobuf/gradle/ProtobufPluginTestHelper.groovy

@@ -38,6 +38,7 @@ final class ProtobufPluginTestHelper {
       .withProjectDir(projectDir)
       .withArguments(args)
       .withGradleVersion(gradleVersion)
+      .withEnvironment(System.getenv()) // Enable forking
       .forwardStdOutput(new OutputStreamWriter(System.out))
       .forwardStdError(new OutputStreamWriter(System.err))
   }