Add NoChiselNamePrefix to ignore instances in @chiselName (#1383)

Add trait chisel3.experimental.NoChiselNamePrefix which causes
@chiselName to skip naming of the instance effectively preventing it
from prefixing any vals inside the instance. It can be applied to
classes such that all instances of that class have this property, or to
individual instances (via creating an anonymous class inline).

Also add basic ScalaDoc for NoChiselNamePrefix and chiselName.

1 files changed, 2 insertions, 0 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/internal/Namer.scala b/chiselFrontend/src/main/scala/chisel3/internal/Namer.scala
index 353e51fd..999971a4 100644
--- a/chiselFrontend/src/main/scala/chisel3/internal/Namer.scala
+++ b/chiselFrontend/src/main/scala/chisel3/internal/Namer.scala
@@ -3,6 +3,7 @@
 // This file contains part of the implementation of the naming static annotation system.
 
 package chisel3.internal.naming
+import chisel3.experimental.NoChiselNamePrefix
 
 import scala.collection.mutable.Stack
 import scala.collection.mutable.ListBuffer
@@ -88,6 +89,7 @@ class NamingContext extends NamingContextInterface {
   def name[T](obj: T, name: String): T = {
     assert(!closed, "Can't name elements after name_prefix called")
     obj match {
+      case _: NoChiselNamePrefix => // Don't name things with NoChiselNamePrefix
       case ref: AnyRef => items += ((ref, name))
       case _ =>
     }