Merge pull request #4139 from retronym/ticket/7965

SI-7965 Support calls to MethodHandle.{invoke,invokeExact}

1 files changed, 54 insertions, 0 deletions

diff --git a/test/files/run/t7965.scala b/test/files/run/t7965.scala
new file mode 100644
index 0000000000..df80d4b5bb
--- /dev/null
+++ b/test/files/run/t7965.scala
@@ -0,0 +1,54 @@
+// Test that scala doesn't apply boxing or varargs conversions to the
+// @PolymorphicSignature magical methods, MethodHandle#{invoke, invokeExact}
+object Test {
+  val code = """
+
+object O {
+  private def foo = "foo"
+  private def bar(x: Int): Int = -x
+  private def baz(x: Box): Unit = x.a = "present"
+  val lookup = java.lang.invoke.MethodHandles.lookup
+}
+
+import java.lang.invoke._
+class Box(var a: Any)
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
+      val mt = MethodType.methodType(ret, params)
+      O.lookup.findVirtual(O.getClass, name, mt)
+    }
+    val fooResult = (lookup("foo", Array(), classOf[String]).invokeExact(O): Int)
+    assert(fooResult == "foo")
+
+    val barResult = (lookup("bar", Array(classOf[Int]), classOf[Int]).invokeExact(O, 42): Int)
+    assert(barResult == -42)
+
+    val box = new Box(null)
+    (lookup("baz", Array(classOf[Box]), Void.TYPE).invokeExact(O, box) : Unit)
+    assert(box.a == "present")
+
+    // Note: Application in statement position in a block in Java also infers return type of Unit,
+    // but we don't support that, ascribe the type to Unit as above.
+    // as done in Java.
+    // lookup("baz", Array(classOf[Box]), Void.TYPE).invokeExact(O, box)
+    ()
+  }
+}
+
+"""
+  def main(args: Array[String]): Unit = {
+    if (util.Properties.isJavaAtLeast("1.7")) test()
+  }
+
+  def test() {
+    import scala.reflect.runtime._
+    import scala.tools.reflect.ToolBox
+
+    val m = currentMirror
+    val tb = m.mkToolBox()
+    import tb._
+    eval(parse(code))
+  }
+}