Generate better names for nodes (#190)

For Chisel nodes defined in Module class-level values of type Option or
Iterable, we can still use reflection to assign names based on the name
of the value. This works for arbitrary nesting of Option and Iterable so
long as the innermost type is HasId. Note that this excludes Maps which
always have an innermost type of Tuple2[_,_].

1 files changed, 21 insertions, 3 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/Module.scala b/chiselFrontend/src/main/scala/chisel3/core/Module.scala
index cde7032d..ca91c5f8 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Module.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Module.scala
@@ -103,10 +103,28 @@ extends HasId {
     val valNames = getValNames(this.getClass)
     def isPublicVal(m: java.lang.reflect.Method) =
       m.getParameterTypes.isEmpty && valNames.contains(m.getName)
+
+    /** Recursively suggests names to supported "container" classes
+      * Arbitrary nestings of supported classes are allowed so long as the
+      * innermost element is of type HasId
+      * Currently supported:
+      *   - Iterable
+      *   - Option
+      * (Note that Map is Iterable[Tuple2[_,_]] and thus excluded)
+      */
+    def nameRecursively(prefix: String, nameMe: Any): Unit =
+      nameMe match {
+        case (id: HasId) => id.suggestName(prefix)
+        case Some(elt) => nameRecursively(prefix, elt)
+        case (iter: Iterable[_]) if iter.hasDefiniteSize =>
+          for ((elt, i) <- iter.zipWithIndex) {
+            nameRecursively(s"${prefix}_${i}", elt)
+          }
+        case _ => // Do nothing
+      }
     val methods = getClass.getMethods.sortWith(_.getName > _.getName)
-    for (m <- methods; if isPublicVal(m)) m.invoke(this) match {
-      case (id: HasId) => id.suggestName(m.getName)
-      case _ =>
+    for (m <- methods if isPublicVal(m)) {
+      nameRecursively(m.getName, m.invoke(this))
     }
 
     // For Module instances we haven't named, suggest the name of the Module