Fix post-merge publishing (#2055)

* Check Unidoc on all versions of Scala

  It is required for publishing and we publish every version

* Fix conflicting cross-version suffixes issue

  When running `sbt ++2.13.4 unidoc`, SBT would set the Scala version
  for the fuzzer and benchmark projects even though they aren't really
  relevant to the command. This may be a misconfiguration or a bug in
  the unidoc plugin. Whatever the case, simply making it possible for
  them to use the same version of Scala as the firrtl project (on which
  they depend) fixes the issue.

* Match versions of Scala in build.sbt and CI

* Fix unidoc issues in 2.13.4

  There is some bug in ScalaDoc not finding some links in firrtl.options
  so those links were made absolute as a workaround.

19 files changed, 55 insertions, 49 deletions

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 18a680f5..31f7ca6a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        scala: [2.13.2, 2.12.12, 2.11.12]
+        scala: [2.13.4, 2.12.13, 2.11.12]
     container:
       image: ucbbar/chisel3-tools
       options: --user github --entrypoint /bin/bash
@@ -34,8 +34,7 @@ jobs:
       - name: Check Formatting (Scala 2.12 only)
         if: matrix.scala == '2.12.12'
         run: sbt ++${{ matrix.scala }} scalafmtCheckAll
-      - name: Unidoc builds (Scala 2.12 only)
-        if: matrix.scala == '2.12.12'
+      - name: Unidoc
         run: sbt ++${{ matrix.scala }} unidoc
       - name: Sanity check benchmarking scripts (Scala 2.12 only)
         if: matrix.scala == '2.12.12'
diff --git a/build.sbt b/build.sbt
index e2c0b19e..76908bb7 100644
--- a/build.sbt
+++ b/build.sbt
@@ -16,13 +16,15 @@ def javacOptionsVersion(scalaVersion: String): Seq[String] = {
   }
 }
 
-
 lazy val commonSettings = Seq(
   organization := "edu.berkeley.cs",
+  scalaVersion := "2.12.13",
+  crossScalaVersions := Seq("2.13.4", "2.12.13", "2.11.12")
+)
+
+lazy val firrtlSettings = Seq(
   name := "firrtl",
   version := "1.5-SNAPSHOT",
-  scalaVersion := "2.12.13",
-  crossScalaVersions := Seq("2.13.4", "2.12.13", "2.11.12"),
   addCompilerPlugin(scalafixSemanticdb),
   scalacOptions := Seq(
     "-deprecation",
@@ -170,6 +172,7 @@ lazy val firrtl = (project in file("."))
     Test / testForkedParallel := true
   )
   .settings(commonSettings)
+  .settings(firrtlSettings)
   .settings(protobufSettings)
   .settings(antlrSettings)
   .settings(assemblySettings)
@@ -187,6 +190,7 @@ lazy val firrtl = (project in file("."))
 
 lazy val benchmark = (project in file("benchmark"))
   .dependsOn(firrtl)
+  .settings(commonSettings)
   .settings(
     assemblyJarName in assembly := "firrtl-benchmark.jar",
     test in assembly := {},
@@ -196,6 +200,7 @@ lazy val benchmark = (project in file("benchmark"))
 val JQF_VERSION = "1.5"
 
 lazy val jqf = (project in file("jqf"))
+  .settings(commonSettings)
   .settings(
     libraryDependencies ++= Seq(
       "edu.berkeley.cs.jqf" % "jqf-fuzz" % JQF_VERSION,
@@ -221,6 +226,7 @@ lazy val testClassAndMethodParser = {
 
 lazy val fuzzer = (project in file("fuzzer"))
   .dependsOn(firrtl)
+  .settings(commonSettings)
   .settings(
     libraryDependencies ++= Seq(
       "com.pholser" % "junit-quickcheck-core" % "0.8",
diff --git a/src/main/scala/firrtl/FileUtils.scala b/src/main/scala/firrtl/FileUtils.scala
index 2cc2961e..f92d50cc 100644
--- a/src/main/scala/firrtl/FileUtils.scala
+++ b/src/main/scala/firrtl/FileUtils.scala
@@ -71,7 +71,7 @@ object FileUtils {
     val ioToDevNull = BasicIO(withIn = false, ProcessLogger(line => sb.append(line)))
 
     try {
-      cmd.run(ioToDevNull).exitValue == 0
+      cmd.run(ioToDevNull).exitValue() == 0
     } catch {
       case _: Throwable => false
     }
diff --git a/src/main/scala/firrtl/LexerHelper.scala b/src/main/scala/firrtl/LexerHelper.scala
index e1327cd7..b755790a 100644
--- a/src/main/scala/firrtl/LexerHelper.scala
+++ b/src/main/scala/firrtl/LexerHelper.scala
@@ -98,7 +98,7 @@ abstract class LexerHelper {
       if (tokenBuffer.isEmpty)
         pullToken()
       else
-        tokenBuffer.dequeue
+        tokenBuffer.dequeue()
 
     if (reachedEof)
       t
@@ -157,6 +157,6 @@ abstract class LexerHelper {
     doPop()
 
     indentations.push(targetIndent)
-    tokenBuffer.dequeue
+    tokenBuffer.dequeue()
   }
 }
diff --git a/src/main/scala/firrtl/LoweringCompilers.scala b/src/main/scala/firrtl/LoweringCompilers.scala
index e27cafb7..e0bde64f 100644
--- a/src/main/scala/firrtl/LoweringCompilers.scala
+++ b/src/main/scala/firrtl/LoweringCompilers.scala
@@ -123,7 +123,7 @@ class NoneCompiler extends Compiler {
 )
 class HighFirrtlCompiler extends Compiler {
   val emitter = new HighFirrtlEmitter
-  def transforms: Seq[Transform] = Forms.HighForm.map(_.getObject)
+  def transforms: Seq[Transform] = Forms.HighForm.map(_.getObject())
 }
 
 /** Emits middle Firrtl input circuit */
@@ -133,7 +133,7 @@ class HighFirrtlCompiler extends Compiler {
 )
 class MiddleFirrtlCompiler extends Compiler {
   val emitter = new MiddleFirrtlEmitter
-  def transforms: Seq[Transform] = Forms.MidForm.map(_.getObject)
+  def transforms: Seq[Transform] = Forms.MidForm.map(_.getObject())
 }
 
 /** Emits lowered input circuit */
@@ -143,7 +143,7 @@ class MiddleFirrtlCompiler extends Compiler {
 )
 class LowFirrtlCompiler extends Compiler {
   val emitter = new LowFirrtlEmitter
-  def transforms: Seq[Transform] = Forms.LowForm.map(_.getObject)
+  def transforms: Seq[Transform] = Forms.LowForm.map(_.getObject())
 }
 
 /** Emits Verilog */
@@ -153,7 +153,7 @@ class LowFirrtlCompiler extends Compiler {
 )
 class VerilogCompiler extends Compiler {
   val emitter = new VerilogEmitter
-  def transforms: Seq[Transform] = Forms.LowFormOptimized.map(_.getObject)
+  def transforms: Seq[Transform] = Forms.LowFormOptimized.map(_.getObject())
 }
 
 /** Emits Verilog without optimizations */
@@ -163,7 +163,7 @@ class VerilogCompiler extends Compiler {
 )
 class MinimumVerilogCompiler extends Compiler {
   val emitter = new MinimumVerilogEmitter
-  def transforms: Seq[Transform] = Forms.LowFormMinimumOptimized.map(_.getObject)
+  def transforms: Seq[Transform] = Forms.LowFormMinimumOptimized.map(_.getObject())
 }
 
 /** Currently just an alias for the [[VerilogCompiler]] */
diff --git a/src/main/scala/firrtl/analyses/ConnectionGraph.scala b/src/main/scala/firrtl/analyses/ConnectionGraph.scala
index 32bb1564..85cbe4df 100644
--- a/src/main/scala/firrtl/analyses/ConnectionGraph.scala
+++ b/src/main/scala/firrtl/analyses/ConnectionGraph.scala
@@ -147,7 +147,7 @@ class ConnectionGraph protected (val circuit: Circuit, val digraph: DiGraph[Refe
     val bfsQueue = new mutable.PriorityQueue[ReferenceTarget]()(ordering)
     bfsQueue.enqueue(root)
     while (bfsQueue.nonEmpty) {
-      val u = bfsQueue.dequeue
+      val u = bfsQueue.dequeue()
       for (v <- getEdges(u)) {
         if (!prev.contains(v) && !blacklist.contains(v)) {
           prev(v) = u
diff --git a/src/main/scala/firrtl/analyses/InstanceGraph.scala b/src/main/scala/firrtl/analyses/InstanceGraph.scala
index 8858c4ea..83a04ca3 100644
--- a/src/main/scala/firrtl/analyses/InstanceGraph.scala
+++ b/src/main/scala/firrtl/analyses/InstanceGraph.scala
@@ -45,7 +45,7 @@ class InstanceGraph(c: Circuit) {
     val topInstance = DefInstance(subTop, subTop)
     instanceQueue.enqueue(topInstance)
     while (instanceQueue.nonEmpty) {
-      val current = instanceQueue.dequeue
+      val current = instanceQueue.dequeue()
       instanceGraph.addVertex(current)
       for (child <- childInstances(current.module)) {
         if (!instanceGraph.contains(child)) {
diff --git a/src/main/scala/firrtl/analyses/InstanceKeyGraph.scala b/src/main/scala/firrtl/analyses/InstanceKeyGraph.scala
index 06c0b377..7584e3c8 100644
--- a/src/main/scala/firrtl/analyses/InstanceKeyGraph.scala
+++ b/src/main/scala/firrtl/analyses/InstanceKeyGraph.scala
@@ -158,7 +158,7 @@ object InstanceKeyGraph {
       val instanceQueue = new mutable.Queue[InstanceKey]
       instanceQueue.enqueue(topInstance)
       while (instanceQueue.nonEmpty) {
-        val current = instanceQueue.dequeue
+        val current = instanceQueue.dequeue()
         instanceGraph.addVertex(current)
         for (child <- childInstanceMap(current.module)) {
           if (!instanceGraph.contains(child)) {
diff --git a/src/main/scala/firrtl/graph/DiGraph.scala b/src/main/scala/firrtl/graph/DiGraph.scala
index b99c6961..3a08d05e 100644
--- a/src/main/scala/firrtl/graph/DiGraph.scala
+++ b/src/main/scala/firrtl/graph/DiGraph.scala
@@ -153,7 +153,7 @@ class DiGraph[T](private[graph] val edges: LinkedHashMap[T, LinkedHashSet[T]]) {
     val queue = new mutable.Queue[T]
     queue.enqueue(root)
     while (queue.nonEmpty) {
-      val u = queue.dequeue
+      val u = queue.dequeue()
       for (v <- getEdges(u)) {
         if (!prev.contains(v) && !blacklist.contains(v)) {
           prev(v) = u
@@ -257,7 +257,7 @@ class DiGraph[T](private[graph] val edges: LinkedHashMap[T, LinkedHashSet[T]]) {
         }
         frame.childCall = None
         while (frame.edgeIter.hasNext && frame.childCall.isEmpty) {
-          val w = frame.edgeIter.next
+          val w = frame.edgeIter.next()
           if (!indices.contains(w)) {
             frame.childCall = Some(w)
             callStack.push(new StrongConnectFrame(w, getEdges(w).iterator))
@@ -269,13 +269,13 @@ class DiGraph[T](private[graph] val edges: LinkedHashMap[T, LinkedHashSet[T]]) {
           if (lowlinks(v) == indices(v)) {
             val scc = new mutable.ArrayBuffer[T]
             do {
-              val w = stack.pop
+              val w = stack.pop()
               onstack -= w
               scc += w
             } while (scc.last != v);
             sccs.append(scc.toSeq)
           }
-          callStack.pop
+          callStack.pop()
         }
       }
     }
@@ -305,7 +305,7 @@ class DiGraph[T](private[graph] val edges: LinkedHashMap[T, LinkedHashSet[T]]) {
     queue += start
     queue ++= linearize.filter(reachable.contains(_))
     while (!queue.isEmpty) {
-      val current = queue.dequeue
+      val current = queue.dequeue()
       for (v <- getEdges(current)) {
         for (p <- paths(current)) {
           addBinding(v, p :+ v)
diff --git a/src/main/scala/firrtl/ir/Serializer.scala b/src/main/scala/firrtl/ir/Serializer.scala
index 7fb30f19..983a7866 100644
--- a/src/main/scala/firrtl/ir/Serializer.scala
+++ b/src/main/scala/firrtl/ir/Serializer.scala
@@ -99,7 +99,7 @@ object Serializer {
     case Block(stmts) =>
       val it = stmts.iterator
       while (it.hasNext) {
-        s(it.next)
+        s(it.next())
         if (it.hasNext) newLineAndIndent()
       }
     case Stop(info, ret, clk, en) =>
diff --git a/src/main/scala/firrtl/options/DependencyManager.scala b/src/main/scala/firrtl/options/DependencyManager.scala
index 39998ed7..5e911940 100644
--- a/src/main/scala/firrtl/options/DependencyManager.scala
+++ b/src/main/scala/firrtl/options/DependencyManager.scala
@@ -91,7 +91,7 @@ trait DependencyManager[A, B <: TransformLike[A] with DependencyAPI[B]] extends
     }
 
     while (queue.nonEmpty) {
-      val u: Dependency[B] = queue.dequeue
+      val u: Dependency[B] = queue.dequeue()
       for (v <- extractor(dependencyToObject(u))) {
         if (!blacklist.contains(v) && !edges.contains(v)) {
           queue.enqueue(v)
@@ -193,13 +193,13 @@ trait DependencyManager[A, B <: TransformLike[A] with DependencyAPI[B]] extends
       )
   }
 
-  /** An ordering of [[firrtl.options.TransformLike TransformLike]]s that causes the requested [[DependencyManager.targets
-    * targets]] to be executed starting from the [[DependencyManager.currentState currentState]]. This ordering respects
+  /** An ordering of [[firrtl.options.TransformLike TransformLike]]s that causes the requested [[firrtl.options.DependencyManager.targets
+    * targets]] to be executed starting from the [[firrtl.options.DependencyManager.currentState currentState]]. This ordering respects
     * prerequisites, optionalPrerequisites, optionalPrerequisiteOf, and invalidates of all constituent
     * [[firrtl.options.TransformLike TransformLike]]s. This uses an algorithm that attempts to reduce the number of
-    * re-lowerings due to invalidations. Re-lowerings are implemented as new [[DependencyManager]]s.
-    * @throws DependencyManagerException if a cycle exists in either the [[DependencyManager.dependencyGraph
-    * dependencyGraph]] or the [[DependencyManager.invalidateGraph invalidateGraph]].
+    * re-lowerings due to invalidations. Re-lowerings are implemented as new [[firrtl.options.DependencyManager]]s.
+    * @throws firrtl.options.DependencyManagerException if a cycle exists in either the [[firrtl.options.DependencyManager.dependencyGraph
+    * dependencyGraph]] or the [[firrtl.options.DependencyManager.invalidateGraph invalidateGraph]].
     */
   lazy val transformOrder: Seq[B] = {
 
@@ -244,8 +244,8 @@ trait DependencyManager[A, B <: TransformLike[A] with DependencyAPI[B]] extends
     l ++ postprocessing
   }
 
-  /** A version of the [[DependencyManager.transformOrder transformOrder]] that flattens the transforms of any internal
-    * [[DependencyManager]]s.
+  /** A version of the [[firrtl.options.DependencyManager.transformOrder transformOrder]] that flattens the transforms of any internal
+    * [[firrtl.options.DependencyManager DependencyManager]]s.
     */
   lazy val flattenedTransformOrder: Seq[B] = transformOrder.flatMap {
     case p: DependencyManager[A, B] => p.flattenedTransformOrder
diff --git a/src/main/scala/firrtl/options/Stage.scala b/src/main/scala/firrtl/options/Stage.scala
index 0783bfb5..cefdd957 100644
--- a/src/main/scala/firrtl/options/Stage.scala
+++ b/src/main/scala/firrtl/options/Stage.scala
@@ -28,7 +28,7 @@ abstract class Stage extends Phase {
   /** Execute this stage on some input annotations. Annotations will be read from any input annotation files.
     * @param annotations input annotations
     * @return output annotations
-    * @throws OptionsException if command line or annotation validation fails
+    * @throws firrtl.options.OptionsException if command line or annotation validation fails
     */
   final def transform(annotations: AnnotationSeq): AnnotationSeq = {
     val annotationsx =
@@ -52,7 +52,7 @@ abstract class Stage extends Phase {
     * @param args command line arguments
     * @param initialAnnotations annotation
     * @return output annotations
-    * @throws OptionsException if command line or annotation validation fails
+    * @throws firrtl.options.OptionsException if command line or annotation validation fails
     */
   final def execute(args: Array[String], annotations: AnnotationSeq): AnnotationSeq =
     transform(shell.parse(args, annotations))
diff --git a/src/main/scala/firrtl/passes/wiring/WiringUtils.scala b/src/main/scala/firrtl/passes/wiring/WiringUtils.scala
index cab6aa5f..6f9b4f83 100644
--- a/src/main/scala/firrtl/passes/wiring/WiringUtils.scala
+++ b/src/main/scala/firrtl/passes/wiring/WiringUtils.scala
@@ -150,11 +150,11 @@ object WiringUtils {
       * sources/sinks not under sinks/sources.
       */
     if (queue.size == 1) {
-      val u = queue.dequeue
+      val u = queue.dequeue()
       sinkInsts.foreach { v => owners(v) = Vector(u) }
     } else {
       while (queue.nonEmpty) {
-        val u = queue.dequeue
+        val u = queue.dequeue()
         visited(u) = true
 
         val edges = (i.graph.getEdges(u.last).map(u :+ _).toVector :+ u.dropRight(1))
@@ -222,11 +222,11 @@ object WiringUtils {
       * sources/sinks not under sinks/sources.
       */
     if (queue.size == 1) {
-      val u = queue.dequeue
+      val u = queue.dequeue()
       sinkInsts.foreach { v => owners(v) = Vector(u) }
     } else {
       while (queue.nonEmpty) {
-        val u = queue.dequeue
+        val u = queue.dequeue()
         visited(u) = true
 
         val edges = i.graph.getEdges(u.last).map(u :+ _).toVector :+ u.dropRight(1)
diff --git a/src/main/scala/firrtl/stage/FirrtlAnnotations.scala b/src/main/scala/firrtl/stage/FirrtlAnnotations.scala
index 2ac74de2..7d0d237a 100644
--- a/src/main/scala/firrtl/stage/FirrtlAnnotations.scala
+++ b/src/main/scala/firrtl/stage/FirrtlAnnotations.scala
@@ -180,7 +180,7 @@ case class RunFirrtlTransformAnnotation(transform: Transform) extends NoTargetAn
 object RunFirrtlTransformAnnotation extends HasShellOptions {
 
   def apply(transform: TransformDependency): RunFirrtlTransformAnnotation =
-    RunFirrtlTransformAnnotation(transform.getObject)
+    RunFirrtlTransformAnnotation(transform.getObject())
 
   private[firrtl] def stringToEmitter(a: String): RunFirrtlTransformAnnotation = {
     val emitter = a match {
diff --git a/src/main/scala/firrtl/stage/phases/DriverCompatibility.scala b/src/main/scala/firrtl/stage/phases/DriverCompatibility.scala
index a37774e5..7ad77212 100644
--- a/src/main/scala/firrtl/stage/phases/DriverCompatibility.scala
+++ b/src/main/scala/firrtl/stage/phases/DriverCompatibility.scala
@@ -58,8 +58,8 @@ object DriverCompatibility {
     def addOptions(p: OptionParser[AnnotationSeq]): Unit = p
       .opt[Unit]("top-name")
       .abbr("tn")
-      .hidden
-      .unbounded
+      .hidden()
+      .unbounded()
       .action((_, _) => throw new OptionsException(optionRemoved("--top-name/-tn")))
   }
 
@@ -71,8 +71,8 @@ object DriverCompatibility {
     def addOptions(p: OptionParser[AnnotationSeq]): Unit = p
       .opt[Unit]("split-modules")
       .abbr("fsm")
-      .hidden
-      .unbounded
+      .hidden()
+      .unbounded()
       .action((_, _) => throw new OptionsException(optionRemoved("--split-modules/-fsm")))
 
   }
diff --git a/src/main/scala/firrtl/transforms/ConstantPropagation.scala b/src/main/scala/firrtl/transforms/ConstantPropagation.scala
index c89fcff1..e4115441 100644
--- a/src/main/scala/firrtl/transforms/ConstantPropagation.scala
+++ b/src/main/scala/firrtl/transforms/ConstantPropagation.scala
@@ -647,7 +647,8 @@ class ConstantPropagation extends Transform with DependencyAPIMigration {
         case WRef(rname, _, kind, _) if betterName(lname, rname) && !swapMap.contains(rname) && kind != PortKind =>
           assert(!swapMap.contains(lname)) // <- Shouldn't be possible because lname is either a
           // node declaration or the single connection to a wire or register
-          swapMap += (lname -> rname, rname -> lname)
+          swapMap += lname -> rname
+          swapMap += rname -> lname
         case _ =>
       }
       nodeMap(lname) = InfoExpr.wrap(info, value)
diff --git a/src/main/scala/firrtl/transforms/ManipulateNames.scala b/src/main/scala/firrtl/transforms/ManipulateNames.scala
index 7be876ef..4a796e58 100644
--- a/src/main/scala/firrtl/transforms/ManipulateNames.scala
+++ b/src/main/scala/firrtl/transforms/ManipulateNames.scala
@@ -464,7 +464,7 @@ abstract class ManipulateNames[A <: ManipulateNames[_]: ClassTag] extends Transf
 
     val block = state.annotations.collect {
       case ManipulateNamesBlocklistAnnotation(targetSeq, t) =>
-        t.getObject match {
+        t.getObject() match {
           case _: A => targetSeq
           case _ => Nil
         }
@@ -473,7 +473,7 @@ abstract class ManipulateNames[A <: ManipulateNames[_]: ClassTag] extends Transf
     val allow = {
       val allowx = state.annotations.collect {
         case ManipulateNamesAllowlistAnnotation(targetSeq, t) =>
-          t.getObject match {
+          t.getObject() match {
             case _: A => targetSeq
             case _ => Nil
           }
@@ -491,13 +491,13 @@ abstract class ManipulateNames[A <: ManipulateNames[_]: ClassTag] extends Transf
     val annotationsx = state.annotations.flatMap {
       /* Consume blocklist annotations */
       case foo @ ManipulateNamesBlocklistAnnotation(_, t) =>
-        t.getObject match {
+        t.getObject() match {
           case _: A => None
           case _ => Some(foo)
         }
       /* Convert allowlist annotations to result annotations */
       case foo @ ManipulateNamesAllowlistAnnotation(a, t) =>
-        t.getObject match {
+        t.getObject() match {
           case _: A =>
             (a, a.map(_.map(renames(_)).flatten)) match {
               case (a, b) => Some(ManipulateNamesAllowlistResultAnnotation(b, t, a))
diff --git a/src/main/scala/logger/LoggerOptions.scala b/src/main/scala/logger/LoggerOptions.scala
index 683d6741..bfd072df 100644
--- a/src/main/scala/logger/LoggerOptions.scala
+++ b/src/main/scala/logger/LoggerOptions.scala
@@ -32,7 +32,7 @@ class LoggerOptions private[logger] (
   }
 
   /** Return the name of the log file, defaults to `a.log` if unspecified */
-  def getLogFileName(): Option[String] = if (!logToFile) None else logFileName.orElse(Some("a.log"))
+  def getLogFileName(): Option[String] = if (!logToFile()) None else logFileName.orElse(Some("a.log"))
 
   /** True if a [[Logger]] should be writing to a file */
   @deprecated("logToFile was removed, use logFileName.nonEmpty", "FIRRTL 1.2")
diff --git a/src/main/scala/tutorial/lesson1-circuit-traversal/AnalyzeCircuit.scala b/src/main/scala/tutorial/lesson1-circuit-traversal/AnalyzeCircuit.scala
index 23ecb114..bab67a74 100644
--- a/src/main/scala/tutorial/lesson1-circuit-traversal/AnalyzeCircuit.scala
+++ b/src/main/scala/tutorial/lesson1-circuit-traversal/AnalyzeCircuit.scala
@@ -142,7 +142,7 @@ class AnalyzeCircuit extends Transform {
     visited match {
       // If e is a [[firrtl.ir.Mux Mux]], increment our ledger and return e.
       case Mux(cond, tval, fval, tpe) =>
-        ledger.foundMux
+        ledger.foundMux()
         e
       // If e is not a [[firrtl.ir.Mux Mux]], return e.
       case notmux => notmux