improve macro hygiene

1 files changed, 4 insertions, 3 deletions

diff --git a/src/main/scala/Chisel/utils.scala b/src/main/scala/Chisel/utils.scala
index 6d073e3d..b0255ef9 100644
--- a/src/main/scala/Chisel/utils.scala
+++ b/src/main/scala/Chisel/utils.scala
@@ -4,7 +4,7 @@ import scala.math._
 import scala.language.reflectiveCalls
 import scala.language.experimental.macros
 import scala.reflect.runtime.universe._
-import scala.reflect.macros.whitebox._
+import scala.reflect.macros.blackbox._
 
 object log2Up
 {
@@ -143,13 +143,14 @@ object is { // Begin deprecation of non-type-parameterized is statements.
 object switch {
   def apply[T <: Bits](cond: T)(x: => Unit): Unit = macro impl
   def impl(c: Context)(cond: c.Tree)(x: c.Tree) = { import c.universe._
+    val sc = c.universe.internal.reificationSupport.freshTermName("sc")
     def extractIsStatement(tree: Tree): List[c.universe.Tree] = tree match {
-      case q"Chisel.is.apply( ..$params )( ..$body )" => List(q"sc.is( ..$params )( ..$body )")
+      case q"Chisel.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )")
       case b => throw new Exception(s"Cannot include blocks that do not begin with is() in switch.")
     }
     val q"..$body" = x
     val ises = body.flatMap(extractIsStatement(_))
-    q"""{ val sc = new SwitchContext($cond); ..$ises }"""
+    q"""{ val $sc = new SwitchContext($cond); ..$ises }"""
   }
 }