Add TargetDirAnnotation to give transforms access (#503)

Also add GlobalCircuitAnnotation for creating similar annotations

3 files changed, 26 insertions, 1 deletions

diff --git a/src/main/scala/firrtl/Driver.scala b/src/main/scala/firrtl/Driver.scala
index 0fe2119d..94cfface 100644
--- a/src/main/scala/firrtl/Driver.scala
+++ b/src/main/scala/firrtl/Driver.scala
@@ -164,8 +164,13 @@ object Driver {
     // Output Annotations
     val outputAnnos = firrtlConfig.getEmitterAnnos(optionsManager)
 
+    // Should these and outputAnnos be moved to loadAnnotations?
+    val globalAnnos = Seq(TargetDirAnnotation(optionsManager.targetDirName))
+
     val finalState = firrtlConfig.compiler.compile(
-      CircuitState(parsedInput, ChirrtlForm, Some(AnnotationMap(firrtlConfig.annotations ++ outputAnnos))),
+      CircuitState(parsedInput,
+                   ChirrtlForm,
+                   Some(AnnotationMap(firrtlConfig.annotations ++ outputAnnos ++ globalAnnos))),
       firrtlConfig.customTransforms
     )
 
diff --git a/src/main/scala/firrtl/ExecutionOptionsManager.scala b/src/main/scala/firrtl/ExecutionOptionsManager.scala
index 7bba50a5..2e95ee0c 100644
--- a/src/main/scala/firrtl/ExecutionOptionsManager.scala
+++ b/src/main/scala/firrtl/ExecutionOptionsManager.scala
@@ -46,6 +46,9 @@ case class CommonOptions(
   }
 }
 
+/** [[annotations.GlobalCircuitAnnotation]] that contains the [[CommonOptions]] target directory */
+object TargetDirAnnotation extends GlobalCircuitAnnotation
+
 trait HasCommonOptions {
   self: ExecutionOptionsManager =>
   var commonOptions = CommonOptions()
diff --git a/src/main/scala/firrtl/annotations/Annotation.scala b/src/main/scala/firrtl/annotations/Annotation.scala
index cbc9bf1c..f96724c6 100644
--- a/src/main/scala/firrtl/annotations/Annotation.scala
+++ b/src/main/scala/firrtl/annotations/Annotation.scala
@@ -41,3 +41,20 @@ object DeletedAnnotation {
     case _ => None
   }
 }
+
+/** Parent class to create global annotations
+  *
+  * These annotations are Circuit-level and available to every transform
+  */
+abstract class GlobalCircuitAnnotation {
+  private lazy val marker = this.getClass.getName
+  def apply(value: String): Annotation =
+    Annotation(CircuitTopName, classOf[Transform], s"$marker:$value")
+  def unapply(a: Annotation): Option[String] = a match {
+    // Assumes transform is already filtered appropriately
+    case Annotation(CircuitTopName, _, str) if str.startsWith(marker) =>
+      Some(str.stripPrefix(s"$marker:"))
+    case _ => None
+  }
+}
+