SI-9437 Emit and support parameter names in class files

JEP 118 added a MethodParameters attribute to the class file spec which
holds the parameter names of methods when compiling Java code with
`javac -parameters`.

We emit parameter names by default now.

2 files changed, 19 insertions, 0 deletions

diff --git a/test/files/run/t9437b/Foo_1.scala b/test/files/run/t9437b/Foo_1.scala
new file mode 100644
index 0000000000..ca6c9c6156
--- /dev/null
+++ b/test/files/run/t9437b/Foo_1.scala
@@ -0,0 +1,3 @@
+class Foo(a: Int, `_`: String, *** : Long, `unary_!` : Float, ABC: Double) {
+  def bar(a: Int, `_`: String, *** : Long, `unary_!` : Float, ABC: Double) = null
+}
diff --git a/test/files/run/t9437b/Test_2.scala b/test/files/run/t9437b/Test_2.scala
new file mode 100644
index 0000000000..521f525f1d
--- /dev/null
+++ b/test/files/run/t9437b/Test_2.scala
@@ -0,0 +1,16 @@
+object Test extends App {
+  val constrParams = classOf[Foo].getConstructors.head.getParameters
+  val methodParams = classOf[Foo].getDeclaredMethods.head.getParameters
+
+  def printParams(params: Array[java.lang.reflect.Parameter]) = {
+    params.foreach { param =>
+      println(s"name: ${param.getName}; isNamePresent: ${param.isNamePresent}; isSynthetic: ${param.isSynthetic}")
+    }
+  }
+
+  printParams(constrParams)
+  printParams(methodParams)
+
+  val foo = new Foo(a = 1, `_` = "2", *** = 3L, `unary_!` = 4.0f, ABC = 5.0)
+  foo.bar(a = 1, `_` = "2", *** = 3L, `unary_!` = 4.0f, ABC = 5.0)
+}