From bb130c128c54cf485fa15ae8ac62777863709a4b Mon Sep 17 00:00:00 2001
From: Cedric Beust <cedric@beust.com>
Date: Sun, 6 Dec 2015 00:06:38 -0800
Subject: [PATCH] Retrolambda plug-in.

---
 .../plugin/retrolambda/RetrolambdaPlugin.kt   | 72 +++++++++++++++++++
 src/main/resources/META-INF/kobalt-plugin.xml |  1 +
 2 files changed, 73 insertions(+)
 create mode 100644 src/main/kotlin/com/beust/kobalt/plugin/retrolambda/RetrolambdaPlugin.kt

diff --git a/src/main/kotlin/com/beust/kobalt/plugin/retrolambda/RetrolambdaPlugin.kt b/src/main/kotlin/com/beust/kobalt/plugin/retrolambda/RetrolambdaPlugin.kt
new file mode 100644
index 00000000..f1782e01
--- /dev/null
+++ b/src/main/kotlin/com/beust/kobalt/plugin/retrolambda/RetrolambdaPlugin.kt
@@ -0,0 +1,72 @@
+package com.beust.kobalt.plugin.retrolambda
+
+import com.beust.kobalt.Plugins
+import com.beust.kobalt.TaskResult
+import com.beust.kobalt.api.ConfigPlugin
+import com.beust.kobalt.api.IClasspathContributor
+import com.beust.kobalt.api.Project
+import com.beust.kobalt.api.annotation.Directive
+import com.beust.kobalt.api.annotation.Task
+import com.beust.kobalt.internal.JvmCompilerPlugin
+import com.beust.kobalt.maven.DependencyManager
+import com.beust.kobalt.maven.dependency.MavenDependency
+import com.beust.kobalt.misc.RunCommand
+import com.google.inject.Inject
+import com.google.inject.Singleton
+import java.io.File
+
+/**
+ * Run Retrolambda on the classes right after "compile". This plug-in automatically downloads and uses
+ * the most recent retrolambda.jar and it can be configured with the `retrolambda{}` directive.
+ */
+@Singleton
+class RetrolambdaPlugin @Inject constructor(val dependencyManager: DependencyManager)
+        : ConfigPlugin<RetrolambdaConfig>(), IClasspathContributor {
+
+    override val name = PLUGIN_NAME
+
+    companion object {
+        const val PLUGIN_NAME = "Retrolambda"
+        const val ID = "net.orfjackal.retrolambda:retrolambda:"
+        val JAR = MavenDependency.create(ID)
+    }
+
+    override fun entriesFor(project: Project?) = listOf(JAR)
+
+    @Task(name = "retrolambda", description = "Run Retrolambda",
+            alwaysRunAfter = arrayOf(JvmCompilerPlugin.TASK_COMPILE))
+    fun taskRetrolambda(project: Project): TaskResult {
+        val config = configurationFor(project)
+        val result = if (config != null) {
+            val classpath = dependencyManager.transitiveClosure(project.compileDependencies).map {
+                it.jarFile.get()
+            }.joinToString(File.separator)
+
+            val args = listOf(
+                    "-Dretrolambda.inputDir=" + project.classesDir(context),
+                    "-Dretrolambda.classpath=" + classpath,
+                    "-Dretrolambda.bytecodeVersion=${config.byteCodeVersion}",
+                    "-jar", JAR.jarFile.get().path)
+
+            val result = RunCommand("java").apply {
+                directory = File(project.directory)
+            }.run(args)
+            TaskResult(result == 0)
+        } else {
+            TaskResult()
+        }
+
+        return result
+    }
+}
+
+class RetrolambdaConfig(var byteCodeVersion: Int = 50) {
+}
+
+@Directive
+fun Project.retrolambda(init: RetrolambdaConfig.() -> Unit) = let {
+    RetrolambdaConfig().apply {
+        init()
+        (Plugins.findPlugin(RetrolambdaPlugin.PLUGIN_NAME) as RetrolambdaPlugin).addConfiguration(it, this)
+    }
+}
diff --git a/src/main/resources/META-INF/kobalt-plugin.xml b/src/main/resources/META-INF/kobalt-plugin.xml
index d1e464ef..1c9f72b5 100644
--- a/src/main/resources/META-INF/kobalt-plugin.xml
+++ b/src/main/resources/META-INF/kobalt-plugin.xml
@@ -12,6 +12,7 @@
         <class-name>com.beust.kobalt.plugin.packaging.PackagingPlugin</class-name>
         <class-name>com.beust.kobalt.plugin.publish.PublishPlugin</class-name>
         <class-name>com.beust.kobalt.plugin.apt.AptPlugin</class-name>
+        <class-name>com.beust.kobalt.plugin.retrolambda.RetrolambdaPlugin</class-name>
 
         <!-- These classes manage -init for Java and Kotlin -->
         <class-name>com.beust.kobalt.plugin.java.JavaBuildGenerator</class-name>