Build native images using GraalVM.

Closes #1123.

src/main/scala/com/typesafe/sbt/packager/graalvm/GraalVMPlugin.scala

@@ -0,0 +1,48 @@
+package com.typesafe.sbt.packager.graalvm
+
+import sbt._
+import sbt.Keys._
+import java.nio.charset.Charset
+
+import com.typesafe.sbt.packager.SettingsHelper
+import com.typesafe.sbt.packager.Keys._
+import com.typesafe.sbt.packager.linux._
+import com.typesafe.sbt.packager.Compat._
+import com.typesafe.sbt.packager.validation._
+
+/**
+  * Plugin to compile ahead-of-time native executables.
+  *
+  * @example Enable the plugin in the `build.sbt`
+  * {{{
+  *    enablePlugins(GraalVMPlugin)
+  * }}}
+  */
+object GraalVMPlugin extends AutoPlugin {
+
+  object autoImport extends GraalVMKeys {
+    val GraalVM: Configuration = config("graalvm")
+  }
+
+  import autoImport._
+
+  override def projectConfigurations: Seq[Configuration] = Seq(GraalVM)
+
+  override lazy val projectSettings = Seq(
+    target in GraalVM := target.value / "graalvm",
+    sourceDirectory in GraalVM := sourceDirectory.value,
+    name in GraalVM := name.value,
+    nativeImageOptions in GraalVM := Seq(s"-H:Name=${(name in GraalVM).value}"),
+    packageBin in GraalVM := {
+      (target in GraalVM).value.mkdirs()
+      val className = (mainClass in Compile).value.getOrElse(sys.error("Meh..."))
+      val classPath = Seq((packageBin in Compile).value) ++ (dependencyClasspath in Compile).value.map(_.data)
+      val arguments = Seq("--class-path", classPath.mkString(":")) ++ (nativeImageOptions in GraalVM).value ++ Seq(className)
+      val command = Seq("native-image") ++ arguments
+      sys.process.Process(command, (target in GraalVM).value) ! streams.value.log match {
+        case 0 => file("K")
+        case x => sys.error("Failed to run native-image, exit status: " + x)
+      }
+    }
+  )
+}

src/main/scala/com/typesafe/sbt/packager/graalvm/Keys.scala

@@ -0,0 +1,12 @@
+package com.typesafe.sbt
+package packager
+package graalvm
+
+import sbt._
+
+/**
+  * GraalVM settings
+  */
+trait GraalVMKeys {
+  val nativeImageOptions = SettingKey[Seq[String]]("native-image-options", "native-image options")
+}

src/sbt-test/graalvm/simple-native-image/build.sbt

@@ -0,0 +1,5 @@
+enablePlugins(GraalVMPlugin)
+
+name := "simple-test"
+
+version := "0.1.0"

src/sbt-test/graalvm/simple-native-image/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % sys.props("project.version"))

src/sbt-test/graalvm/simple-native-image/src/main/scala/Main.scala

@@ -0,0 +1,5 @@
+object Main {
+  def main(args: Array[String]): Unit = {
+    println("Hello world")
+  }
+}

src/sbt-test/graalvm/simple-native-image/test

@@ -0,0 +1,3 @@
+# Generate the GraalVM native image
+> show graalvm:packageBin
+$ exists target/graalvm/simple-test

src/sphinx/formats/graalvm.rst

@@ -0,0 +1,47 @@
+.. _graalvm-plugin:
+
+GraalVM Plugin
+=============
+
+GraalVM's ``native-image`` compiles Java programs AOT (ahead-of-time).
+
+  https://www.graalvm.org/docs/reference-manual/aot-compilation/ documents the AOT compilation of GraalVM.
+
+.. note:: The GraalVM plugin depends on the :ref:`universal-plugin`.
+
+Requirements
+------------
+
+You must have ``native-image`` of GraalVM in your classpath.
+
+Build
+-----
+
+.. code-block:: bash
+
+  sbt 'show graalvm:packageBin'
+
+
+Required Settings
+~~~~~~~~~~~~~~~~~
+
+.. code-block:: scala
+
+  enablePlugins(GraalVMPlugin)
+
+
+Settings
+--------
+
+Publishing Settings
+~~~~~~~~~~~~~~~~~~~
+
+  ``nativeImageOptions``
+    Extra options that will be passed to the ``native-image`` command. By default, this includes the name of the main class.
+
+Tasks
+-----
+The GraalVM plugin provides the following commands:
+
+  ``graalvm:packageBin``
+    Generates a native image using GraalVM.