1 files changed, 66 insertions, 0 deletions
diff --git a/src/reflect/scala/reflect/internal/Phase.scala b/src/reflect/scala/reflect/internal/Phase.scala
new file mode 100644
index 0000000000..68dc5ce783
--- /dev/null
+++ b/src/reflect/scala/reflect/internal/Phase.scala
@@ -0,0 +1,66 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2011 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+
+package scala.reflect
+package internal
+
+abstract class Phase(val prev: Phase) {
+  if ((prev ne null) && (prev ne NoPhase))
+    prev.nx = this
+
+  type Id = Int
+  val id: Id = if (prev eq null) 0 else prev.id + 1
+
+  /** New flags visible after this phase has completed */
+  def nextFlags: Long = 0l
+
+  /** New flags visible once this phase has started */
+  def newFlags: Long = 0l
+
+  val fmask = (
+    if (prev eq null) Flags.InitialFlags
+    else prev.flagMask | prev.nextFlags | newFlags
+  )
+  def flagMask: Long = fmask
+
+  private var nx: Phase = this
+
+  def next: Phase = nx
+  def hasNext = next != this
+  def iterator = Iterator.iterate(this)(_.next) takeWhile (p => p.next != p)
+
+  def name: String
+  def description: String = name
+  // Will running with -Ycheck:name work?
+  def checkable: Boolean = true
+  def specialized: Boolean = false
+  def erasedTypes: Boolean = false
+  def flatClasses: Boolean = false
+  def refChecked: Boolean = false
+
+  /** This is used only in unsafeTypeParams, and at this writing is
+   *  overridden to false in parser, namer, typer, and erasure. (And NoPhase.)
+   */
+  def keepsTypeParams = true
+  def run(): Unit
+
+  override def toString() = name
+  override def hashCode = id.## + name.##
+  override def equals(other: Any) = other match {
+    case x: Phase   => id == x.id && name == x.name
+    case _          => false
+  }
+}
+
+object NoPhase extends Phase(null) {
+  def name = "<no phase>"
+  override def keepsTypeParams = false
+  def run() { throw new Error("NoPhase.run") }
+}
+
+object SomePhase extends Phase(NoPhase) {
+  def name = "<some phase>"
+  def run() { throw new Error("SomePhase.run") }
+}