chore(build): Port includeClassDirectories support to Kotlin

Author: bric3

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/BuildTimeInstrumentationExtension.kt

@@ -1,5 +1,6 @@
 package datadog.gradle.plugin.instrument
 
+import org.gradle.api.file.ConfigurableFileCollection
 import org.gradle.api.file.DirectoryProperty
 import org.gradle.api.provider.ListProperty
 
@@ -23,4 +24,9 @@ abstract class BuildTimeInstrumentationExtension {
    * Additional classpath entries required to resolve instrumentation plugins and their dependencies.
    */
   abstract val additionalClasspath: ListProperty<DirectoryProperty>
+
+  /**
+   * Additional class directories to include in instrumentation processing.
+   */
+  abstract val includeClassDirectories: ConfigurableFileCollection
 }

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/BuildTimeInstrumentationPlugin.kt

@@ -130,6 +130,7 @@ class BuildTimeInstrumentationPlugin : Plugin<Project> {
         inputs.property("javaVersion", resolvedJavaVersion)
         inputs.property("plugins", extension.plugins)
         inputs.files(extension.additionalClasspath)
+        inputs.files(extension.includeClassDirectories)
 
         // Temporary location for raw (un-instrumented) classes.
         val tmpUninstrumentedClasses = project.objects.directoryProperty().value(
@@ -154,6 +155,7 @@ class BuildTimeInstrumentationPlugin : Plugin<Project> {
             instrumentingClassPath,
             destinationDirectory,
             tmpUninstrumentedClasses,
+            extension.includeClassDirectories,
           )
         )
 

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/InstrumentAction.kt

@@ -44,6 +44,15 @@ abstract class InstrumentAction : WorkAction<InstrumentWorkParameters> {
         from(originalClassesDirectory)
         into(tmpUninstrumentedDir)
       }
+      // Merge any additional class directories (e.g. unpacked dependency JARs) to be processed
+      parameters.includeClassDirectories.files.forEach { classesDir ->
+        if (classesDir.exists()) {
+          fileSystemOperations.copy {
+            from(classesDir)
+            into(tmpUninstrumentedDir)
+          }
+        }
+      }
       fileSystemOperations.delete {
         delete(objects.fileTree().from(originalClassesDirectory))
       }

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/InstrumentPostProcessingAction.kt

@@ -21,7 +21,8 @@ abstract class InstrumentPostProcessingAction @Inject constructor(
   val plugins: ListProperty<String>,
   val instrumentingClassPath: FileCollection,
   val compilerOutputDirectory: DirectoryProperty,
-  val tmpDirectory: DirectoryProperty
+  val tmpDirectory: DirectoryProperty,
+  val includeClassDirectories: FileCollection
 ) : Action<Task> {
   private val logger = Logging.getLogger(InstrumentPostProcessingAction::class.java)
   private val resolvedJavaVersion: JavaLanguageVersion = when (javaVersion) {
@@ -61,6 +62,7 @@ abstract class InstrumentPostProcessingAction @Inject constructor(
       instrumentingClassPath.setFrom(action.instrumentingClassPath)
       compilerOutputDirectory.set(action.compilerOutputDirectory)
       tmpDirectory.set(action.tmpDirectory)
+      includeClassDirectories.setFrom(action.includeClassDirectories)
     }
   }
 

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/InstrumentWorkParameters.kt

@@ -13,4 +13,5 @@ interface InstrumentWorkParameters : WorkParameters {
   val instrumentingClassPath: ConfigurableFileCollection
   val compilerOutputDirectory: DirectoryProperty
   val tmpDirectory: DirectoryProperty
+  val includeClassDirectories: ConfigurableFileCollection
 }