Another lap around the track with generic signa...

Another lap around the track with generic signatures. At the root of the
issue reported in #4214 is our old friend (fondly remembered from the
days of primitive equality) boxed/primitive unification.

  // scala
  trait T[A] {
    def f(): A
  }
  // the generic signature spec doesn't allow for parameterizing
  // on primitive types, so this cannot remain Char.  However
  // translating it to Character, as was done, also has issues.
  class C extends T[Char] {
    def f(): Char = 'a'
  }

  // Note that neither of the signatures for f, the implementation // or
  the bridge method, matches the type parameter. Generic interfaces in
  class: T<java.lang.Character> Generic signatures: public char C.f()
  public java.lang.Object C.f()

After this commit, primitive type parameters are translated into Object
instead of the boxed type. It was martin's idea, so no review. Closes
#4214.

1 files changed, 20 insertions, 0 deletions

diff --git a/test/files/run/primitive-sigs-2.scala b/test/files/run/primitive-sigs-2.scala
new file mode 100644
index 0000000000..a8876f7f60
--- /dev/null
+++ b/test/files/run/primitive-sigs-2.scala
@@ -0,0 +1,20 @@
+trait T[A] {
+  def f(): A
+}
+class C extends T[Char] {
+  def f(): Char = 'a'
+}
+
+object Test {
+  val c1: Class[_] = classOf[T[_]]
+  val c2: Class[_] = classOf[C]
+
+  val c1m = c1.getMethods.toList filter (_.getName == "f") map (_.getGenericReturnType.toString)
+  val c2m = c2.getMethods.toList filter (_.getName == "f") map (_.getGenericReturnType.toString)
+
+  def main(args: Array[String]): Unit = {
+    println(c2.getGenericInterfaces.map(_.toString).sorted mkString " ")
+    println(c1m ++ c2m sorted)
+    println(new C f)
+  }
+}