Use toBytes, not getBytes, in CustomFileEmission

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

src/main/scala/firrtl/Emitter.scala

@@ -107,12 +107,12 @@ sealed trait EmittedAnnotation[T <: EmittedComponent] extends NoTargetAnnotation
 }
 sealed trait EmittedCircuitAnnotation[T <: EmittedCircuit] extends EmittedAnnotation[T] {
 
-  override def toBytes = Some(value.value.getBytes)
+  override def getBytes = value.value.getBytes
 
 }
 sealed trait EmittedModuleAnnotation[T <: EmittedModule] extends EmittedAnnotation[T] {
 
-  override def toBytes = Some(value.value.getBytes)
+  override def getBytes = value.value.getBytes
 
 }
 

src/main/scala/firrtl/options/StageAnnotations.scala

@@ -49,10 +49,10 @@ trait CustomFileEmission { this: Annotation =>
     *
     * If you only need to serialize a string, you can use the `getBytes` method:
     * {{{
-    *  def toBytes: Option[Iterable[Byte]] = Some(myString.getBytes)
+    *  def getBytes: Iterable[Byte] = myString.getBytes
     * }}}
     */
-  def toBytes: Option[Iterable[Byte]]
+  def getBytes: Iterable[Byte]
 
   /** Optionally, a sequence of annotations that will replace this annotation in the output annotation file.
     *

src/main/scala/firrtl/options/phases/WriteOutputAnnotations.scala

@@ -36,13 +36,13 @@ class WriteOutputAnnotations extends Phase {
         val filename = a.filename(annotations)
         val canonical = filename.getCanonicalPath()
 
-        (a.toBytes, filesWritten.get(canonical)) match {
-          case (Some(x), None) =>
+        filesWritten.get(canonical) match {
+          case None =>
             val w = new BufferedWriter(new FileWriter(filename))
-            x.foreach( w.write(_) )
+            a.getBytes.foreach( w.write(_) )
             w.close()
             filesWritten(canonical) = a
-          case (Some(_), Some(first)) =>
+          case Some(first) =>
             val msg =
               s"""|Multiple CustomFileEmission annotations would be serialized to the same file, '$canonical'
                   |  - first writer:
@@ -53,7 +53,6 @@ class WriteOutputAnnotations extends Phase {
                   |      trimmed serialization: ${a.serialize.take(80)}
                   |""".stripMargin
             throw new PhaseException(msg)
-          case (None, _) =>
         }
         a.replacements(filename)
       case a => Some(a)

src/test/scala/firrtlTests/options/phases/WriteOutputAnnotationsSpec.scala

@@ -156,7 +156,7 @@ private object WriteOutputAnnotationsSpec {
 
     override protected def suffix: Option[String] = Some(".Emission")
 
-    override def toBytes: Option[Iterable[Byte]] = Some(value.getBytes)
+    override def getBytes: Iterable[Byte] = value.getBytes
 
     override def replacements(file: File): AnnotationSeq = Seq(Replacement(file.toString))