Filter ResolvePaths in EliminateTargetPaths (#1310)

Change EliminateTargetPaths to remove ResolvePaths annotations in the
output AnnotationSeq. This prevents a bug whereby the upstream
ResolvePaths annotations from previous runs of EliminateTargetPaths
can result in unexpected duplication.

Adds a test that checks that ResolvePaths annotations are actually
removed.

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

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

2 files changed, 21 insertions, 3 deletions

diff --git a/src/main/scala/firrtl/annotations/transforms/EliminateTargetPaths.scala b/src/main/scala/firrtl/annotations/transforms/EliminateTargetPaths.scala
index f6bab6ea..2f20430b 100644
--- a/src/main/scala/firrtl/annotations/transforms/EliminateTargetPaths.scala
+++ b/src/main/scala/firrtl/annotations/transforms/EliminateTargetPaths.scala
@@ -133,10 +133,13 @@ class EliminateTargetPaths extends Transform {
 
   override protected def execute(state: CircuitState): CircuitState = {
 
-    val annotations = state.annotations.collect { case a: ResolvePaths => a }
+    val (annotations, annotationsx) = state.annotations.partition{
+      case a: ResolvePaths => true
+      case _               => false
+    }
 
     // Collect targets that are not local
-    val targets = annotations.flatMap(_.targets.collect { case x: IsMember => x })
+    val targets = annotations.map(_.asInstanceOf[ResolvePaths]).flatMap(_.targets.collect { case x: IsMember => x })
 
     // Check validity of paths in targets
     val instanceOfModules = new InstanceGraph(state.circuit).getChildrenInstanceOfModule
@@ -162,6 +165,6 @@ class EliminateTargetPaths extends Transform {
 
     val (newCircuit, renameMap) = run(state.circuit, targets)
 
-    state.copy(circuit = newCircuit, renames = Some(renameMap))
+    state.copy(circuit = newCircuit, renames = Some(renameMap), annotations = annotationsx)
   }
 }
diff --git a/src/test/scala/firrtlTests/annotationTests/EliminateTargetPathsSpec.scala b/src/test/scala/firrtlTests/annotationTests/EliminateTargetPathsSpec.scala
index c75e0914..7aac277f 100644
--- a/src/test/scala/firrtlTests/annotationTests/EliminateTargetPathsSpec.scala
+++ b/src/test/scala/firrtlTests/annotationTests/EliminateTargetPathsSpec.scala
@@ -357,4 +357,19 @@ class EliminateTargetPathsSpec extends FirrtlPropSpec with FirrtlMatchers {
       outputLines should contain (line)
     }
   }
+
+  property("It should remove ResolvePaths annotations") {
+      val input =
+      """|circuit Foo:
+         |  module Bar:
+         |    skip
+         |  module Foo:
+         |    inst bar of Bar
+         |""".stripMargin
+
+    CircuitState(passes.ToWorkingIR.run(Parser.parse(input)), UnknownForm, Nil)
+      .resolvePaths(Seq(CircuitTarget("Foo").module("Foo").instOf("bar", "Bar")))
+      .annotations
+      .collect{ case a: firrtl.annotations.transforms.ResolvePaths => a } should be (empty)
+  }
 }