Ensure unique names for definitions in the async block.

 - transform the provided tree using reflect.internal.Symbols#Symbol.name_=
   and treeCopy.{Ident, Select}.
    - not sure if this is possible within the public Symbol API.
 - move checking for unsupported nested module/class to AsyncAnalysis.
 - make block merging selective (only do so if there are nested await calls.)

2 files changed, 33 insertions, 32 deletions

diff --git a/src/test/scala/scala/async/TreeInterrogation.scala b/src/test/scala/scala/async/TreeInterrogation.scala
index 02f4b43..9e68005 100644
--- a/src/test/scala/scala/async/TreeInterrogation.scala
+++ b/src/test/scala/scala/async/TreeInterrogation.scala
@@ -32,6 +32,6 @@ class TreeInterrogation {
     val varDefs = tree1.collect {
       case ValDef(mods, name, _, _) if mods.hasFlag(Flag.MUTABLE) => name
     }
-    varDefs.map(_.decoded).toSet mustBe(Set("state$async", "onCompleteHandler$async", "await$1$1", "await$2$1"))
+    varDefs.map(_.decoded).toSet mustBe(Set("state$async", "onCompleteHandler$async", "await$1", "await$2"))
   }
 }
diff --git a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
index 1d6e09a..872e44d 100644
--- a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
+++ b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
@@ -112,37 +112,38 @@ class AnfTransformSpec {
     State.result mustBe (14)
   }
 
-  // TODO JZ
-//  @Test
-//  def `inlining block produces duplicate definition`() {
-//    import scala.async.AsyncId
-//
-//    AsyncId.async {
-//      val f = 12
-//      val x = AsyncId.await(f)
-//
-//      {
-//        val x = 42
-//        println(x)
-//      }
-//
-//      x
-//    }
-//  }
-//  @Test
-//  def `inlining block in tail position produces duplicate definition`() {
-//    import scala.async.AsyncId
-//
-//    AsyncId.async {
-//      val f = 12
-//      val x = AsyncId.await(f)
-//
-//      {
-//        val x = 42 // TODO should we rename the symbols when we collapse them into the same scope?
-//        x
-//      }
-//    } mustBe (42)
-//  }
+  @Test
+  def `inlining block does not produce duplicate definition`() {
+    import scala.async.AsyncId
+
+    AsyncId.async {
+      val f = 12
+      val x = AsyncId.await(f)
+
+      {
+        type X = Int
+        val x: X = 42
+        println(x)
+      }
+      type X = Int
+      x: X
+    }
+  }
+
+  @Test
+  def `inlining block in tail position does not produce duplicate definition`() {
+    import scala.async.AsyncId
+
+    AsyncId.async {
+      val f = 12
+      val x = AsyncId.await(f)
+
+      {
+        val x = 42
+        x
+      }
+    } mustBe (42)
+  }
 
   @Test
   def `match as expression 1`() {