1 files changed, 39 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/reflect/WrappedProperties.scala b/src/compiler/scala/tools/reflect/WrappedProperties.scala
new file mode 100644
index 0000000000..2ca374cf01
--- /dev/null
+++ b/src/compiler/scala/tools/reflect/WrappedProperties.scala
@@ -0,0 +1,39 @@
+/* NSC -- new Scala compiler
+ * Copyright 2006-2011 LAMP/EPFL
+ * @author  Paul Phillips
+ */
+
+package scala.tools
+package reflect
+
+import scala.util.PropertiesTrait
+import java.security.AccessControlException
+
+/** For placing a wrapper function around property functions.
+ *  Motivated by places like google app engine throwing exceptions
+ *  on property lookups.
+ */
+trait WrappedProperties extends PropertiesTrait {
+  def wrap[T](body: => T): Option[T]
+
+  protected def propCategory   = "wrapped"
+  protected def pickJarBasedOn = this.getClass
+
+  override def propIsSet(name: String)               = wrap(super.propIsSet(name)) exists (x => x)
+  override def propOrElse(name: String, alt: String) = wrap(super.propOrElse(name, alt)) getOrElse alt
+  override def setProp(name: String, value: String)  = wrap(super.setProp(name, value)) orNull
+  override def clearProp(name: String)               = wrap(super.clearProp(name)) orNull
+  override def envOrElse(name: String, alt: String)  = wrap(super.envOrElse(name, alt)) getOrElse alt
+  override def envOrNone(name: String)               = wrap(super.envOrNone(name)).flatten
+
+  def systemProperties: Iterator[(String, String)] = {
+    import scala.collection.JavaConverters._
+    wrap(System.getProperties.asScala.iterator) getOrElse Iterator.empty
+  }
+}
+
+object WrappedProperties {
+  object AccessControl extends WrappedProperties {
+    def wrap[T](body: => T) = try Some(body) catch { case _: AccessControlException => None }
+  }
+}