SI-2577, SI-6860: annotation type inference.

This is less than ideal:

  scala> class Bippy[T] extends annotation.StaticAnnotation
  defined class Bippy

  scala> def f: Int @Bippy = 5
  f: Int @Bippy[T]

Turns out we can infer such types. Now it says:

  scala> def f: Int @Bippy = 5
  f: Int @Bippy[Nothing]

This should put to rest many an issue with parameterized
annotations.

5 files changed, 73 insertions, 0 deletions

diff --git a/test/files/pos/annotations2.scala b/test/files/pos/annotations2.scala
new file mode 100644
index 0000000000..3bce7f8ac4
--- /dev/null
+++ b/test/files/pos/annotations2.scala
@@ -0,0 +1,31 @@
+
+class B[T](x: (T, T)) {
+  def this(xx: (T, Any, Any)) = this((xx._1, xx._1))
+}
+class BAnn[T](x: (T, T)) extends scala.annotation.StaticAnnotation {
+  def this(xx: (T, Any, Any)) = this((xx._1, xx._1))
+}
+class CAnn[T](x: (T, T)) extends scala.annotation.StaticAnnotation {
+  def this(xx: Class[T]) = this((xx.newInstance(), xx.newInstance()))
+}
+
+class A1 {
+  val b1 = new B((1, 2, 3))
+  val b2 = new B((1, 2))
+  val b3 = new B[Int]((1, 2, 3))
+  val b4 = new B[Int]((1, 2))
+}
+
+class A2 {
+  @BAnn((1, 2, 3)) val b1 = null
+  @BAnn((1, 2)) val b2 = null
+  @BAnn[Int]((1, 2, 3)) val b3 = null
+  @BAnn[Int]((1, 2)) val b4 = null
+}
+
+class A3 {
+  @CAnn(classOf[Int]) val b1 = null
+  @CAnn((1, 2)) val b2 = null
+  @CAnn[Int](classOf[Int]) val b3 = null
+  @CAnn[Int]((1, 2)) val b4 = null
+}
diff --git a/test/files/run/t2577.check b/test/files/run/t2577.check
new file mode 100644
index 0000000000..4a584e4989
--- /dev/null
+++ b/test/files/run/t2577.check
@@ -0,0 +1 @@
+Nothing
diff --git a/test/files/run/t2577.scala b/test/files/run/t2577.scala
new file mode 100644
index 0000000000..6d836a3996
--- /dev/null
+++ b/test/files/run/t2577.scala
@@ -0,0 +1,17 @@
+case class annot[T]() extends scala.annotation.StaticAnnotation
+
+// type inference should infer @annot[Nothing] instead of @annot[T]
+// note the T is not in scope here!
+class Foo[@annot U]
+
+object Test {
+  import scala.reflect.runtime.universe._
+  val x = new Foo
+
+  def main(args: Array[String]): Unit = {
+    val targ = typeOf[x.type].widen match {
+      case TypeRef(_, _, arg :: _) => arg
+    }
+    println(targ)
+  }
+}
diff --git a/test/files/run/t6860.check b/test/files/run/t6860.check
new file mode 100644
index 0000000000..c96331f540
--- /dev/null
+++ b/test/files/run/t6860.check
@@ -0,0 +1,4 @@
+Bippy[String]
+Bippy[String]
+throws[Nothing]
+throws[RuntimeException]
diff --git a/test/files/run/t6860.scala b/test/files/run/t6860.scala
new file mode 100644
index 0000000000..2dcc2a67f7
--- /dev/null
+++ b/test/files/run/t6860.scala
@@ -0,0 +1,20 @@
+class Bippy[T](val value: T) extends annotation.StaticAnnotation
+
+class A {
+  @Bippy("hi") def f1: Int = 1
+  @Bippy[String]("hi") def f2: Int = 2
+
+  @throws("what do I throw?") def f3 = throw new RuntimeException
+  @throws[RuntimeException]("that's good to know!") def f4 = throw new RuntimeException
+}
+
+object Test {
+  import scala.reflect.runtime.universe._
+
+  def main(args: Array[String]): Unit = {
+    val members = typeOf[A].declarations.toList
+    val tpes = members flatMap (_.annotations) map (_.tpe)
+
+    tpes.map(_.toString).sorted foreach println
+  }
+}