Address review comments (remove dead/debug code, +comments)

src/compiler/scala/tools/nsc/Global.scala

@@ -579,7 +579,7 @@ class Global(var currentSettings: Settings, reporter0: Reporter)
   object async extends {
     val global: Global.this.type = Global.this
     val runsAfter = List("posterasure")
-    val runsRightAfter = Some("posterasure")
+    val runsRightAfter = None
   } with AsyncPhase
 
   // phaseName = "lambdalift"
@@ -1013,7 +1013,7 @@ class Global(var currentSettings: Settings, reporter0: Reporter)
        definitions.isDefinitionsInitialized
     && rootMirror.isMirrorInitialized
   )
-  override def isPastTyper = globalPhase != null && isPast(currentRun.typerPhase)
+  override def isPastTyper = isPast(currentRun.typerPhase)
   def isPast(phase: Phase) = (
        (curRun ne null)
     && isGlobalInitialized // defense against init order issues
@@ -1350,7 +1350,6 @@ class Global(var currentSettings: Settings, reporter0: Reporter)
     def runIsAt(ph: Phase)   = globalPhase.id == ph.id
     def runIsAtOptimiz       = runIsAt(jvmPhase)
 
-    firstPhase.iterator.foreach(_.init())
     isDefined = true
 
     // ----------- Units and top-level classes and objects --------

src/compiler/scala/tools/nsc/backend/jvm/opt/BoxUnbox.scala

@@ -21,7 +21,6 @@ import scala.tools.asm.Opcodes._
 import scala.tools.asm.Type
 import scala.tools.asm.tree._
 import scala.tools.nsc.backend.jvm.BTypes.InternalName
-import scala.tools.nsc.backend.jvm.analysis.BackendUtils
 import scala.tools.nsc.backend.jvm.opt.BytecodeUtils._
 
 abstract class BoxUnbox {

src/compiler/scala/tools/nsc/transform/UnCurry.scala

@@ -20,7 +20,6 @@ import scala.collection.mutable
 import scala.collection.mutable.ListBuffer
 import scala.reflect.internal.util.ListOfNil
 import PartialFunction.cond
-import scala.reflect.NameTransformer
 
 /*<export> */
 /** - uncurry all symbol and tree types (@see UnCurryPhase) -- this includes normalizing all proper types.

src/compiler/scala/tools/nsc/transform/async/AsyncAnalysis.scala

@@ -13,7 +13,6 @@
 package scala.tools.nsc.transform.async
 
 import scala.collection.mutable.ListBuffer
-import scala.reflect.NameTransformer
 
 trait AsyncAnalysis extends TransformUtils  {
   import global._

src/compiler/scala/tools/nsc/transform/async/AsyncPhase.scala

@@ -35,6 +35,7 @@ abstract class AsyncPhase extends Transform with TypingTransformers with AnfTran
 
   /**
    * Mark the given method as requiring an async transform.
+   * Refer to documentation in the public API that forwards to this method in src/reflect/scala/reflect/api/Internals.scala
    */
   final def markForAsyncTransform(owner: Symbol, method: DefDef, awaitMethod: Symbol,
                                   config: Map[String, AnyRef]): DefDef = {

src/compiler/scala/tools/nsc/typechecker/Implicits.scala

@@ -327,10 +327,7 @@ trait Implicits {
    */
   def memberWildcardType(name: Name, tp: Type) = {
     val result = refinedType(List(WildcardType), NoSymbol)
-    val owner = result.typeSymbol orElse { // TODO async (when after erasure?)...
-      val clazz = NoSymbol.newRefinementClass(NoPosition)
-      clazz setInfo RefinedType(Nil, newScope, clazz)
-    }
+    val owner = result.typeSymbol
     (name match {
       case x: TermName => owner.newMethod(x)
       case x: TypeName => owner.newAbstractType(x)

src/compiler/scala/tools/reflect/FastTrack.scala

@@ -44,9 +44,6 @@ class FastTrack[MacrosAndAnalyzer <: Macros with Analyzer](val macros: MacrosAnd
   private def makeWhitebox(sym: Symbol)(pf: PartialFunction[Applied, MacroContext => Tree]) =
     sym -> new FastTrackEntry(pf, isBlackbox = false)
 
-  private def makeBlackBoxIfExists(sym_pf: (Symbol, PartialFunction[Applied, MacroContext => Tree])) =
-    sym_pf match { case (sym, _) if !sym.exists => Map.empty case (sym, pf) => Map(makeBlackbox(sym)(pf))}
-
   final class FastTrackEntry(pf: PartialFunction[Applied, MacroContext => Tree], val isBlackbox: Boolean) extends (MacroArgs => Any) {
     def validate(tree: Tree) = pf isDefinedAt Applied(tree)
     def apply(margs: MacroArgs): margs.c.Expr[Nothing] = {

src/partest-extras/scala/tools/partest/async/Async.scala

@@ -18,7 +18,6 @@ import scala.language.experimental.macros
 import scala.annotation.compileTimeOnly
 import scala.concurrent.{ExecutionContext, Future, Promise}
 import scala.reflect.macros.blackbox
-import scala.tools.nsc.transform.async.StateAssigner
 import scala.util.{Failure, Success, Try}
 
 object Async {

src/partest-extras/scala/tools/partest/async/CompletableFutureAwait.scala

@@ -19,7 +19,6 @@ import java.util.function.BiConsumer
 import scala.annotation.compileTimeOnly
 import scala.language.experimental.macros
 import scala.reflect.macros.blackbox
-import scala.tools.nsc.transform.async.StateAssigner
 import scala.util.{Failure, Success, Try}
 
 object CompletableFutureAwait {

src/partest-extras/scala/tools/partest/async/OutputAwait.scala

@@ -17,7 +17,6 @@ import scala.collection.immutable.HashMap
 import scala.collection.mutable
 import scala.language.experimental.macros
 import scala.reflect.macros.blackbox
-import scala.tools.nsc.transform.async.StateAssigner
 
 object OutputAwait {
   def writing[T](body: T): Output[T] = macro impl

src/reflect/scala/reflect/api/Internals.scala

@@ -374,6 +374,17 @@ trait Internals { self: Universe =>
      */
     def boundedWildcardType(bounds: TypeBounds): BoundedWildcardType
 
+    /** Mark the given `DefDef` for later processing by the `async` phase of the compiler
+     *
+     * @param owner current owner the owner of the call site being transformed into an async state machine
+     * @param method A method of the form `def $name($paramName: $ParamType): $T = $CODE`, where calls to `$CODE`
+     *               `awaitSymbol` in `$CODE` mark continuation points.
+     * @param awaitSymbol The `await` method, of a typically of a type like `[T](Future[T): T`
+     * @param config      Untyped channel for additional configuration parameters. This currently allows
+     *                     - "postAnfTransform" : A function from `Block => Block`
+     *                     - "stateDiagram"     : A function from `(Symbol, Tree) => Option[String => Unit]` that can
+     *                                            opt to receive a .dot diagram of the state machine.
+     */
     def markForAsyncTransform(owner: Symbol, method: DefDef, awaitSymbol: Symbol, config: Map[String, AnyRef]): DefDef = method
 
     /** Syntactic conveniences for additional internal APIs for trees, symbols and types */

src/reflect/scala/reflect/internal/Phase.scala

@@ -64,7 +64,6 @@ abstract class Phase(val prev: Phase) extends Ordered[Phase] {
    *  overridden to false in parser, namer, typer, and erasure. (And NoPhase.)
    */
   def keepsTypeParams = true
-  def init(): Unit = ()
   def run(): Unit
 
   override def toString() = name

src/reflect/scala/reflect/internal/StdAttachments.scala

@@ -122,6 +122,4 @@ trait StdAttachments {
 
   // When typing a Def with this attachment, change the owner of its RHS from origalOwner to the symbol of the Def
   case class ChangeOwnerAttachment(originalOwner: Symbol)
-
-  case object SuppressPureExpressionWarning extends PlainAttachment
 }

src/reflect/scala/reflect/internal/TreeInfo.scala

@@ -232,7 +232,6 @@ abstract class TreeInfo {
       (    !tree.isErrorTyped
         && (isExprSafeToInline(tree) || isWarnableRefTree)
         && isWarnableSymbol
-        && !tree.hasAttachment[SuppressPureExpressionWarning.type]
       )
   }
 

src/reflect/scala/reflect/internal/Trees.scala

@@ -478,14 +478,7 @@ trait Trees extends api.Trees {
   case class ArrayValue(elemtpt: Tree, elems: List[Tree]) extends TermTree
 
   case class Function(vparams: List[ValDef], body: Tree)
-       extends SymTree with TermTree with FunctionApi {
-
-    override def tpe_=(tp: Type): Unit = {
-      if (!definitions.isFunctionType(tp))
-        new Throwable().printStackTrace()
-      super.setType(tp)
-    }
-  }
+       extends SymTree with TermTree with FunctionApi
   object Function extends FunctionExtractor
 
   case class Assign(lhs: Tree, rhs: Tree)
@@ -1538,7 +1531,6 @@ trait Trees extends api.Trees {
   }
 
   class ChangeOwnerTraverser(val oldowner: Symbol, val newowner: Symbol) extends Traverser {
-    assert(newowner != NoSymbol, oldowner)
     final def change(sym: Symbol) = {
       if (sym != NoSymbol && sym.owner == oldowner) {
         sym.owner = newowner

src/reflect/scala/reflect/runtime/JavaUniverseForce.scala

@@ -64,7 +64,6 @@ trait JavaUniverseForce { self: runtime.JavaUniverse  =>
     this.TypeParamVarargsAttachment
     this.KnownDirectSubclassesCalled
     this.ChangeOwnerAttachment
-    this.SuppressPureExpressionWarning
     this.noPrint
     this.typeDebug
     // inaccessible: this.posAssigner