1 files changed, 23 insertions, 0 deletions
diff --git a/examples/scala-js/library/src/main/scala/scala/scalajs/runtime/UndefinedBehaviorError.scala b/examples/scala-js/library/src/main/scala/scala/scalajs/runtime/UndefinedBehaviorError.scala
new file mode 100644
index 0000000..b06ed7d
--- /dev/null
+++ b/examples/scala-js/library/src/main/scala/scala/scalajs/runtime/UndefinedBehaviorError.scala
@@ -0,0 +1,23 @@
+package scala.scalajs.runtime
+
+import scala.util.control.ControlThrowable
+
+/** Error thrown when an undefined behavior in Fatal mode has been detected.
+ *  This error should never be caught. It indicates a severe programming bug.
+ *  In Unchecked mode, the program may behave arbitrarily.
+ *  The `cause` is set to the exception that would have been thrown if the
+ *  given behavior was in Compliant mode.
+ *  If your program relies on the proper kind of exception being thrown, as if
+ *  running on the JVM, you should set the appropriate behavior to Compliant.
+ *  Note that this will have (potentially major) performance impacts.
+ */
+class UndefinedBehaviorError(message: String, cause: Throwable)
+    extends java.lang.Error(message, cause) with ControlThrowable {
+
+  def this(cause: Throwable) =
+    this("An undefined behavior was detected" +
+        (if (cause == null) "" else ": "+cause.getMessage), cause)
+
+  override def fillInStackTrace(): Throwable =
+    super[Error].fillInStackTrace()
+}