Enabled variance checking

Variance checking is now run as part of type-checking.

Fixed tests that exhibited variance errors. Added tests where some classes of
variance errors should be detected.

2 files changed, 69 insertions, 0 deletions

diff --git a/tests/neg/t1843-variances.scala b/tests/neg/t1843-variances.scala
new file mode 100644
index 000000000..e9b5c5d2d
--- /dev/null
+++ b/tests/neg/t1843-variances.scala
@@ -0,0 +1,25 @@
+/**
+* Scala Compiler Will Crash On this File
+* ... Or Will It?
+*
+*/
+
+object Crash {
+  trait UpdateType[A]
+  case class StateUpdate[+A](updateType : UpdateType[A], value : A)
+  case object IntegerUpdateType extends UpdateType[Integer]
+
+  //However this method will cause a crash
+  def crash(updates: List[StateUpdate[_]]): Unit = {
+    updates match {
+      case Nil =>
+      case u::us =>
+        u match {
+          //Line below seems to be the crashing line
+          case StateUpdate(key, newValue) if (key == IntegerUpdateType) =>
+            println("Requires a statement to induce the crash")
+          case _ =>
+        }
+    }
+  }
+}
diff --git a/tests/neg/variances.scala b/tests/neg/variances.scala
new file mode 100644
index 000000000..30390ad22
--- /dev/null
+++ b/tests/neg/variances.scala
@@ -0,0 +1,44 @@
+// Tests variance checking on default methods
+import reflect.ClassTag
+
+class Foo[+A: ClassTag](x: A) {
+
+  private[this] val elems: Array[A] = Array(x)
+
+  def f[B](x: Array[B] = elems): Array[B] = x // (1) should give a variance error here or ...
+
+}
+
+object Test extends App {
+
+  val foo: Foo[Object] = new Foo[String]("A")
+
+  val arr = foo.f[Object]()
+
+  arr(0) = new Integer(1) // (1) ... will give an ArrayStoreException here
+
+}
+
+class Outer[+A](x: A) {
+
+  private[this] var elem: A = x
+
+  def getElem: A = elem
+
+  class Inner(constrParam: A) {  // (2) should give a variance error here or ...
+    elem = constrParam
+  }
+
+}
+
+object Test2 extends App {
+  val o1: Outer[String] = new Outer[String]("A")
+  val o2: Outer[Object] = o1
+  new o2.Inner(new Integer(1))
+
+  val x: String = o1.getElem  // (2) ... will give a classcast exeption here
+
+}
+
+
+