Remove the warning on kotlin plugin warning (#9711)

* fix: Kotlin plugin warning

Build scripts use the `buildscript` way to configure the project's plugins, which is not recommended anymore since quite a few versions in gradle.

```
The Kotlin Gradle plugin was loaded multiple times in different subprojects, which is not supported and may break the build.
This might happen in subprojects that apply the Kotlin plugins with the Gradle 'plugins { ... }' DSL if they specify explicit versions, even if the versions are equal.
Please add the Kotlin plugin to the common parent project or the root project, then remove the versions in the subprojects.
If the parent project does not need the plugin, add 'apply false' to the plugin line.
See: https://docs.gradle.org/current/userguide/plugins.html#sec:subprojects_plugins_dsl
The Kotlin plugin was loaded in the following projects: ':dd-java-agent:agent-ci-visibility', ':dd-java-agent:agent-llmobs'
```

* style: make scalafmt happy

* style: make google-java-format happy

* fix: Exclude generated files and more generally anything in the build directory

* fix: Single kotlin plugin version but configure each projects

Author: bric3

build.gradle.kts

@@ -13,6 +13,7 @@ plugins {
   id("com.gradleup.shadow") version "8.3.6" apply false
   id("me.champeau.jmh") version "0.7.3" apply false
   id("org.gradle.playframework") version "0.13" apply false
+  kotlin("jvm") version libs.versions.kotlin.plugin apply false
 }
 
 description = "dd-trace-java"

buildSrc/src/main/groovy/InstrumentPlugin.groovy

@@ -35,7 +35,7 @@ class InstrumentPlugin implements Plugin<Project> {
     InstrumentExtension extension = project.extensions.create('instrument', InstrumentExtension)
 
     project.tasks.matching {
-      it.name in ['compileJava', 'compileScala', 'compileKotlin', 'compileGroovy'] ||
+      it.name in ['compileJava', 'compileScala', 'compileGroovy'] ||
         it.name =~ /compileMain_.+Java/
     }.all {
       AbstractCompile compileTask = it as AbstractCompile

dd-java-agent/agent-ci-visibility/build.gradle

@@ -1,31 +1,8 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 
-buildscript {
-  repositories {
-    mavenLocal()
-    if (project.rootProject.hasProperty("gradlePluginProxy")) {
-      maven {
-        url project.rootProject.property("gradlePluginProxy")
-        allowInsecureProtocol = true
-      }
-    }
-    if (project.rootProject.hasProperty("mavenRepositoryProxy")) {
-      maven {
-        url project.rootProject.property("mavenRepositoryProxy")
-        allowInsecureProtocol = true
-      }
-    }
-    gradlePluginPortal()
-    mavenCentral()
-  }
-
-  dependencies {
-    classpath group: 'org.jetbrains.kotlin', name: 'kotlin-gradle-plugin', version: libs.versions.kotlin.get()
-  }
-}
-
 plugins {
   id 'com.gradleup.shadow'
+  id 'org.jetbrains.kotlin.jvm' version libs.versions.kotlin.plugin
 }
 
 apply from: "$rootDir/gradle/java.gradle"

dd-java-agent/agent-llmobs/build.gradle

@@ -1,23 +1,24 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
-
-buildscript {
-  repositories {
-    mavenCentral()
-  }
-
-  dependencies {
-    classpath group: 'org.jetbrains.kotlin', name: 'kotlin-gradle-plugin', version: libs.versions.kotlin.get()
-  }
-}
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 
 plugins {
   id 'com.gradleup.shadow'
+  id 'org.jetbrains.kotlin.jvm'
 }
 
 apply from: "$rootDir/gradle/java.gradle"
 apply from: "$rootDir/gradle/version.gradle"
 apply from: "$rootDir/gradle/test-with-kotlin.gradle"
 
+kotlin {
+  compilerOptions {
+    jvmTarget = JvmTarget.JVM_1_8
+    apiVersion = KotlinVersion.KOTLIN_1_6
+    languageVersion = KotlinVersion.KOTLIN_1_6
+  }
+}
+
 minimumBranchCoverage = 0.0
 minimumInstructionCoverage = 0.0
 

dd-java-agent/benchmark-integration/play-perftest/app/controllers/HomeController.scala

@@ -7,14 +7,12 @@ import javax.inject.Inject
 
 import play.api.mvc._
 
-/**
-  * This controller creates an `Action` to handle HTTP requests to the
+/** This controller creates an `Action` to handle HTTP requests to the
   * application's work page which does busy wait to simulate some work
   */
-class HomeController @Inject()(cc: ControllerComponents) extends AbstractController(cc) {
+class HomeController @Inject() (cc: ControllerComponents) extends AbstractController(cc) {
 
-  /**
-    * Create an Action to perform busy wait
+  /** Create an Action to perform busy wait
     */
   def doGet(workTimeMS: Option[Long], error: Option[String]) = Action {
     implicit request: Request[AnyContent] =>

dd-java-agent/instrumentation/akka/akka-actor-2.5/src/akka23Test/scala/AkkaActors.scala

@@ -78,24 +78,27 @@ class AkkaActors extends AutoCloseable {
 
 object AkkaActors {
   // If we can't load the Version class, then assume 2.3
-  val isAkka23: Boolean = try {
-    Class.forName("akka.Version")
-    false
-  } catch {
-    case _: Throwable => true
-  }
+  val isAkka23: Boolean =
+    try {
+      Class.forName("akka.Version")
+      false
+    } catch {
+      case _: Throwable => true
+    }
 
   // The way to terminate an actor system has changed between versions
   val terminate: (ActorSystem) => Unit = {
-    val t = try {
-      ActorSystem.getClass.getMethod("terminate")
-    } catch {
-      case _: Throwable => try {
-        ActorSystem.getClass.getMethod("awaitTermination")
+    val t =
+      try {
+        ActorSystem.getClass.getMethod("terminate")
       } catch {
-        case _: Throwable => null
+        case _: Throwable =>
+          try {
+            ActorSystem.getClass.getMethod("awaitTermination")
+          } catch {
+            case _: Throwable => null
+          }
       }
-    }
     if (t ne null) {
       { system: ActorSystem =>
         t.invoke(system)