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.)

1 files changed, 1 insertions, 9 deletions

diff --git a/src/main/scala/scala/async/ExprBuilder.scala b/src/main/scala/scala/async/ExprBuilder.scala
index 573af16..b7cfc8f 100644
--- a/src/main/scala/scala/async/ExprBuilder.scala
+++ b/src/main/scala/scala/async/ExprBuilder.scala
@@ -32,7 +32,7 @@ final class ExprBuilder[C <: Context, FS <: FutureSystem](override val c: C, val
     val tr                = newTermName("tr")
     val onCompleteHandler = suffixedName("onCompleteHandler")
 
-    def fresh(name: TermName) = newTermName(c.fresh("" + name + "$"))
+    def fresh(name: TermName) = if (name.toString.contains("$")) name else newTermName(c.fresh("" + name + "$"))
   }
 
   private[async] lazy val futureSystemOps = futureSystem.mkOps(c)
@@ -335,14 +335,6 @@ final class ExprBuilder[C <: Context, FS <: FutureSystem](override val c: C, val
         currState = afterMatchState
         stateBuilder = new builder.AsyncStateBuilder(currState, toRename)
 
-      case ClassDef(_, name, _, _) =>
-        // do not allow local class definitions, because of SI-5467 (specific to case classes, though)
-        c.error(stat.pos, s"Local class ${name.decoded} illegal within `async` block")
-
-      case ModuleDef(_, name, _) =>
-        // local object definitions lead to spurious type errors (because of resetAllAttrs?)
-        c.error(stat.pos, s"Local object ${name.decoded} illegal within `async` block")
-
       case _ =>
         checkForUnsupportedAwait(stat)
         stateBuilder += stat