2 files changed, 28 insertions, 0 deletions
diff --git a/src/main/scala/firrtl/annotations/Annotation.scala b/src/main/scala/firrtl/annotations/Annotation.scala
index 2e361833..9efc6e9b 100644
--- a/src/main/scala/firrtl/annotations/Annotation.scala
+++ b/src/main/scala/firrtl/annotations/Annotation.scala
@@ -3,6 +3,9 @@
 package firrtl
 package annotations
 
+import net.jcazevedo.moultingyaml._
+import firrtl.annotations.AnnotationYamlProtocol._
+
 case class AnnotationException(message: String) extends Exception(message)
 
 final case class Annotation(target: Named, transform: Class[_ <: Transform], value: String) {
@@ -26,3 +29,15 @@ final case class Annotation(target: Named, transform: Class[_ <: Transform], val
   def check(from: Named, tos: Seq[Named], which: Annotation): Unit = {}
   def duplicate(n: Named) = Annotation(n, transform, value)
 }
+
+object DeletedAnnotation {
+  def apply(xFormName: String, anno: Annotation): Annotation =
+    Annotation(anno.target, classOf[Transform], s"""DELETED by $xFormName\n${AnnotationUtils.toYaml(anno)}""")
+
+  private val deletedRegex = """(?s)DELETED by ([^\n]*)\n(.*)""".r
+  def unapply(a: Annotation): Option[Tuple2[String, Annotation]] = a match {
+    case Annotation(named, t, deletedRegex(xFormName, annoString)) if t == classOf[Transform] =>
+      Some((xFormName, AnnotationUtils.fromYaml(annoString)))
+    case _ => None
+  }
+}
diff --git a/src/main/scala/firrtl/annotations/AnnotationUtils.scala b/src/main/scala/firrtl/annotations/AnnotationUtils.scala
index 6e6af81d..8f55c13e 100644
--- a/src/main/scala/firrtl/annotations/AnnotationUtils.scala
+++ b/src/main/scala/firrtl/annotations/AnnotationUtils.scala
@@ -3,9 +3,15 @@
 package firrtl
 package annotations
 
+import net.jcazevedo.moultingyaml._
+import firrtl.annotations.AnnotationYamlProtocol._
+
 import firrtl.ir._
 
 object AnnotationUtils {
+  def toYaml(a: Annotation): String = a.toYaml.prettyPrint
+  def fromYaml(s: String): Annotation = s.parseYaml.convertTo[Annotation]
+
   /** Returns true if a valid Module name */
   val SerializedModuleName = """([a-zA-Z_][a-zA-Z_0-9~!@#$%^*\-+=?/]*)""".r
   def validModuleName(s: String): Boolean = s match {
@@ -34,6 +40,13 @@ object AnnotationUtils {
     case None => Seq(s)
   }
 
+  def toNamed(s: String): Named = tokenize(s) match {
+    case Seq(n) => CircuitName(n)
+    case Seq(c, m) => ModuleName(m, CircuitName(c))
+    case Seq(c, m) => ModuleName(m, CircuitName(c))
+    case Seq(c, m, x) => ComponentName(x, ModuleName(m, CircuitName(c)))
+  }
+
   /** Given a serialized component/subcomponent reference, subindex, subaccess,
    *  or subfield, return the corresponding IR expression.
    *  E.g. "foo.bar" becomes SubField(Reference("foo", UnknownType), "bar", UnknownType)