Add a way to know thew classloader of the class in the callsite

Author: nicolasstucki

library/src/scala/quoted/Toolbox.scala

@@ -16,9 +16,16 @@ object Toolbox {
     implicit def make(implicit settings: Settings): Toolbox = Toolbox.make
   }
 
-  def make2(obj: Any)(implicit settings: Settings): Toolbox = {
+  @forceInline def make4(implicit settings: Settings): Toolbox = {
+    // TODO find the name of the class that needs to be loaded. Maybe from a stack trace.
+
+    // We force inline to make forName use the classloader of the class at callsite
+    val cl = Class.forName("hello.Main").getClassLoader
+    make2(cl)
+  }
+
+  def make2(cl: ClassLoader)(implicit settings: Settings): Toolbox = {
     try {
-      val cl = obj.getClass().getClassLoader()
       val toolboxImplCls = cl.loadClass("dotty.tools.dotc.quoted.ToolboxImpl")
       val makeMeth = toolboxImplCls.getMethod("make2", classOf[Settings], classOf[ClassLoader])
       makeMeth.invoke(null, settings, cl).asInstanceOf[Toolbox]

sbt-dotty/sbt-test/sbt-dotty/quoted-example-project/src/main/scala/hello/Hello.scala

@@ -5,7 +5,10 @@ import scala.quoted._
 
 object Main {
 
-  implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make2(this)
+//  val cl = Class.forName("hello.Main").getClassLoader
+//  implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make2(cl)
+
+  implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make4
 
   def main(args: Array[String]): Unit = {
     val square = stagedPower(2)