Attempt to get a basic truffle build going

build.sbt

@@ -197,8 +197,41 @@ lazy val bench = project
   .settings(
     publish := {},
     publishLocal := {},
-    libraryDependencies ++=
-      Seq(),
-    publishArtifact := false)
-  .settings(coverageEnabled := false)
+    libraryDependencies ++= Seq(),
+    publishArtifact := false,
+    coverageEnabled := false
+  )
   .enablePlugins(JmhPlugin)
+
+lazy val pathToTruffleDsl = taskKey[String]("Path to truffle-dsl")
+
+lazy val truffle = project
+  .dependsOn(core.jvm, cli)
+  .settings(moduleName := "bosatsu-truffle")
+  .settings(commonSettings)
+  .settings(
+    pathToTruffleDsl := {
+      val classpath = (Compile / dependencyClasspath).value
+      val myLibraryDependency = classpath.find(_.data.getName.contains("truffle-dsl-processor")).getOrElse(
+        throw new RuntimeException("truffle-dsl-processor dependency not found")
+      )
+      println(myLibraryDependency.data.getAbsolutePath())
+      myLibraryDependency.data.getAbsolutePath
+    },
+    javacOptions ++= Seq(
+      "-processorpath",
+      pathToTruffleDsl.value,
+      "-Xlint:processing"
+    ),
+    libraryDependencies ++= Seq(
+      "org.graalvm.truffle" % "truffle-api" % "22.3.1",
+      "org.graalvm.truffle" % "truffle-dsl-processor" % "22.3.1",
+      "org.scalameta" %% "munit" % "0.7.29" % Test
+    ),
+    run / fork := true,
+    javaOptions ++= Seq("-ea",
+      "--add-exports", "org.graalvm.truffle/com.oracle.truffle.api=ALL-UNNAMED",
+      "--add-exports", "org.graalvm.truffle/com.oracle.truffle.api.nodes=ALL-UNNAMED",
+      "--add-exports", "org.graalvm.truffle/com.oracle.truffle.api.staticobject=ALL-UNNAMED"
+    )
+  )

truffle/src/main/java/org/bykn/bosatsu/truffle/AdditionNode.java

@@ -0,0 +1,9 @@
+package org.bykn.bosatsu.truffle;
+import com.oracle.truffle.api.dsl.NodeChild;
+
+  @NodeChild("leftNode")  @NodeChild("rightNode")
+public abstract class AdditionNode extends BosatsuNode {
+    protected int addInts(int leftValue, int rightValue) {
+        return leftValue + rightValue;
+    }
+}

truffle/src/main/java/org/bykn/bosatsu/truffle/BosatsuNode.java

@@ -0,0 +1,8 @@
+package org.bykn.bosatsu.truffle;
+
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.nodes.Node;
+
+public abstract class BosatsuNode extends Node {
+  public abstract int executeInt(VirtualFrame frame);
+}

truffle/src/main/java/org/bykn/bosatsu/truffle/BosatsuRootNode.java

@@ -0,0 +1,21 @@
+package org.bykn.bosatsu.truffle;
+
+import com.oracle.truffle.api.nodes.RootNode;
+import com.oracle.truffle.api.frame.VirtualFrame;
+
+class BosatsuRootNode extends RootNode {
+    @SuppressWarnings("FieldMayBeFinal")
+    @Child
+    private BosatsuNode exprNode;
+
+    public BosatsuRootNode(BosatsuNode exprNode) {
+        super(null);
+
+        this.exprNode = exprNode;
+    }
+
+    @Override
+    public Object execute(VirtualFrame frame) {
+        return this.exprNode.executeInt(frame);
+    }
+}

truffle/src/main/java/org/bykn/bosatsu/truffle/IntNode.java

@@ -0,0 +1,16 @@
+package org.bykn.bosatsu.truffle;
+
+import com.oracle.truffle.api.frame.VirtualFrame;
+
+public class IntNode extends BosatsuNode {
+  private final int value;
+
+  public IntNode(int value) {
+    this.value = value;
+  }
+
+  @Override
+  public int executeInt(VirtualFrame frame) {
+    return this.value;
+  }
+}

truffle/src/test/scala/org/bykn/bosatsu/truffle/TruffleTest.scala

@@ -0,0 +1,15 @@
+package org.bykn.bosatsu.truffle
+
+class TruffleTest extends munit.FunSuite {
+  test("add 12+32") {
+    val exprNode = AdditionNodeGen.create(
+        new IntNode(12),
+        new IntNode(34));
+    val rootNode = new BosatsuRootNode(exprNode)
+    val callTarget = rootNode.getCallTarget()
+
+    val result = callTarget.call()
+
+    assertEquals(46, result);
+  }
+}