Make TopWiringTransform idempotent

This changes TopWiringTransform to remove TopWiringAnnotations after
it runs.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/main/scala/firrtl/transforms/TopWiring.scala b/src/main/scala/firrtl/transforms/TopWiring.scala
index 65281382..fb6f73b4 100644
--- a/src/main/scala/firrtl/transforms/TopWiring.scala
+++ b/src/main/scala/firrtl/transforms/TopWiring.scala
@@ -261,7 +261,13 @@ class TopWiringTransform extends Transform {
       val newCircuit = state.circuit.copy(modules = modulesx)
       val fixedCircuit = fixupCircuit(newCircuit)
       val mappings = sources(state.circuit.main).zipWithIndex
-      (state.copy(circuit = fixedCircuit), mappings)
+
+      val annosx = state.annotations.filter {
+        case _: TopWiringAnnotation => false
+        case _                      => true
+      }
+
+      (state.copy(circuit = fixedCircuit, annotations = annosx), mappings)
     }
     else { (state, List.empty) }
     //Generate output files based on the mapping.