jsr45 scala

A.scala

object A {
  def main(args: Array[String]): Unit = {
    val testVar = "hai"
    val res = B.foo(testVar)
    println(res)
  }
}

B.scala

object B {
  @inline def foo(x: String) = {
    val fooVar = "mix"
    C.bar(x + fooVar)
  }
}

C.scala

object C {
  @inline def bar(x: String) = {
    val barVar = "mux"
    x + barVar
  }
}

JSR54.scala

import java.io.{InputStreamReader, OutputStreamWriter}

import com.sun.jdi.{Bootstrap, ClassType, VMDisconnectedException}
import com.sun.jdi.event.{ClassPrepareEvent, EventSet}

import scala.jdk.CollectionConverters._

/*
Copied and adapted from https://itsallbinary.com/java-debug-interface-api-jdi-hello-world-example-programmatic-debugging-for-beginners/

qsc -cp $JAVA_HOME/lib/tools.jar JSR45.scala
qsc A.scala B.scala C.scala -opt:l:inline '-opt-inline-from:**'
qs -cp .:$JAVA_HOME/lib/tools.jar JSR45 . A 'A$'
*/

object JSR45 {
  def main(args: Array[String]) = {
    val cp = args(0)
    val main = args(1)
    val debug = args(2)

    val launchingConnector = Bootstrap.virtualMachineManager.defaultConnector
    val env = launchingConnector.defaultArguments
    env.get("main").setValue(main)
    val options = env.get("options")
    options.setValue(s"-cp $cp")
    val vm = launchingConnector.launch(env)
    val classPrepareRequest = vm.eventRequestManager.createClassPrepareRequest
    classPrepareRequest.addClassFilter(debug)
    classPrepareRequest.enable()
    var eventSet: EventSet = null
    try {
      while ({ eventSet = vm.eventQueue.remove(100); eventSet != null }) {
        println(eventSet.asScala.toList)
        for (event <- eventSet.asScala) {
          event match {
            case evt: ClassPrepareEvent =>
              val classType = evt.referenceType.asInstanceOf[ClassType]
              println(classType)
              println(classType.defaultStratum)
              println(classType.allLineLocations)
              println(classType.allLineLocations("ScalaDebug", null))

            case _ =>
          }
          vm.resume()
        }
      }
    } catch {
      case _: VMDisconnectedException =>
        System.out.println("VM is now disconnected.")
      case e: Exception =>
        e.printStackTrace()
    } finally {
      val reader = new InputStreamReader(vm.process.getInputStream)
      val writer = new OutputStreamWriter(System.out)
      val buf    = new Array[Char](1024)
      reader.read(buf)
      writer.write(buf)
      writer.flush()
    }
  }
}