Merge pull request #2103 from adriaanm/bin-compatv2.10.1-RC1

Forward and backward binary compatibility between 2.10.0 and 2.10.1-RC1

12 files changed, 160 insertions, 178 deletions

diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala
index 9765e7c52f..2d6952ff92 100644
--- a/src/library/scala/collection/immutable/List.scala
+++ b/src/library/scala/collection/immutable/List.scala
@@ -643,6 +643,10 @@ object List extends SeqFactory[List] {
 }
 
 /** Only used for list serialization */
+@SerialVersionUID(0L - 8287891243975527522L)
+private[scala] case object ListSerializeStart
+
+/** Only used for list serialization */
 @SerialVersionUID(0L - 8476791151975527571L)
 private[scala] case object ListSerializeEnd
 
diff --git a/src/library/scala/collection/immutable/Range.scala b/src/library/scala/collection/immutable/Range.scala
index 02c10700b1..802e16605d 100644
--- a/src/library/scala/collection/immutable/Range.scala
+++ b/src/library/scala/collection/immutable/Range.scala
@@ -77,7 +77,6 @@ extends scala.collection.AbstractSeq[Int]
   final val terminalElement = start + numRangeElements * step
 
   override def last = if (isEmpty) Nil.last else lastElement
-  override def head = if (isEmpty) Nil.head else start
 
   override def min[A1 >: Int](implicit ord: Ordering[A1]): Int =
     if (ord eq Ordering.Int) {
diff --git a/src/library/scala/collection/mutable/MutableList.scala b/src/library/scala/collection/mutable/MutableList.scala
index fd92d2e555..bc6272bfdb 100644
--- a/src/library/scala/collection/mutable/MutableList.scala
+++ b/src/library/scala/collection/mutable/MutableList.scala
@@ -61,7 +61,8 @@ extends AbstractSeq[A]
     tl
   }
 
-  protected final def tailImpl(tl: MutableList[A]) {
+  // this method must be private for binary compatibility
+  private final def tailImpl(tl: MutableList[A]) {
     require(nonEmpty, "tail of empty list")
     tl.first0 = first0.tail
     tl.len = len - 1
diff --git a/src/library/scala/collection/mutable/Queue.scala b/src/library/scala/collection/mutable/Queue.scala
index b947fa3cca..8ef5f6aeb7 100644
--- a/src/library/scala/collection/mutable/Queue.scala
+++ b/src/library/scala/collection/mutable/Queue.scala
@@ -167,6 +167,13 @@ extends MutableList[A]
    */
   def front: A = head
 
+  // this method (duplicated from MutableList) must be private for binary compatibility
+  private final def tailImpl(tl: Queue[A]) {
+    require(nonEmpty, "tail of empty list")
+    tl.first0 = first0.tail
+    tl.len = len - 1
+    tl.last0 = if (tl.len == 0) tl.first0 else last0
+  }
 
   // TODO - Don't override this just for new to create appropriate type....
   override def tail: Queue[A] = {
diff --git a/src/library/scala/concurrent/BatchingExecutor.scala b/src/library/scala/concurrent/BatchingExecutor.scala
deleted file mode 100644
index a0d7aaea47..0000000000
--- a/src/library/scala/concurrent/BatchingExecutor.scala
+++ /dev/null
@@ -1,117 +0,0 @@
-/*                     __                                               *\
-**     ________ ___   / /  ___     Scala API                            **
-**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
-**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
-** /____/\___/_/ |_/____/_/ | |                                         **
-**                          |/                                          **
-\*                                                                      */
-
-package scala.concurrent
-
-import java.util.concurrent.Executor
-import scala.annotation.tailrec
-
-/**
- * Mixin trait for an Executor
- * which groups multiple nested `Runnable.run()` calls
- * into a single Runnable passed to the original
- * Executor. This can be a useful optimization
- * because it bypasses the original context's task
- * queue and keeps related (nested) code on a single
- * thread which may improve CPU affinity. However,
- * if tasks passed to the Executor are blocking
- * or expensive, this optimization can prevent work-stealing
- * and make performance worse. Also, some ExecutionContext
- * may be fast enough natively that this optimization just
- * adds overhead.
- * The default ExecutionContext.global is already batching
- * or fast enough not to benefit from it; while
- * `fromExecutor` and `fromExecutorService` do NOT add
- * this optimization since they don't know whether the underlying
- * executor will benefit from it.
- * A batching executor can create deadlocks if code does
- * not use `scala.concurrent.blocking` when it should,
- * because tasks created within other tasks will block
- * on the outer task completing.
- * This executor may run tasks in any order, including LIFO order.
- * There are no ordering guarantees.
- *
- * WARNING: The underlying Executor's execute-method must not execute the submitted Runnable
- * in the calling thread synchronously. It must enqueue/handoff the Runnable.
- */
-private[concurrent] trait BatchingExecutor extends Executor {
-
-  // invariant: if "_tasksLocal.get ne null" then we are inside BatchingRunnable.run; if it is null, we are outside
-  private val _tasksLocal = new ThreadLocal[List[Runnable]]()
-
-  private class Batch(val initial: List[Runnable]) extends Runnable with BlockContext {
-    private var parentBlockContext: BlockContext = _
-    // this method runs in the delegate ExecutionContext's thread
-    override def run(): Unit = {
-      require(_tasksLocal.get eq null)
-
-      val prevBlockContext = BlockContext.current
-      BlockContext.withBlockContext(this) {
-        try {
-          parentBlockContext = prevBlockContext
-
-          @tailrec def processBatch(batch: List[Runnable]): Unit = batch match {
-            case Nil => ()
-            case head :: tail =>
-              _tasksLocal set tail
-              try {
-                head.run()
-              } catch {
-                case t: Throwable =>
-                  // if one task throws, move the
-                  // remaining tasks to another thread
-                  // so we can throw the exception
-                  // up to the invoking executor
-                  val remaining = _tasksLocal.get
-                  _tasksLocal set Nil
-                  unbatchedExecute(new Batch(remaining)) //TODO what if this submission fails?
-                  throw t // rethrow
-              }
-              processBatch(_tasksLocal.get) // since head.run() can add entries, always do _tasksLocal.get here
-          }
-
-          processBatch(initial)
-        } finally {
-          _tasksLocal.remove()
-          parentBlockContext = null
-        }
-      }
-    }
-
-    override def blockOn[T](thunk: => T)(implicit permission: CanAwait): T = {
-      // if we know there will be blocking, we don't want to keep tasks queued up because it could deadlock.
-      {
-        val tasks = _tasksLocal.get
-        _tasksLocal set Nil
-        if ((tasks ne null) && tasks.nonEmpty)
-          unbatchedExecute(new Batch(tasks))
-      }
-
-      // now delegate the blocking to the previous BC
-      require(parentBlockContext ne null)
-      parentBlockContext.blockOn(thunk)
-    }
-  }
-
-  protected def unbatchedExecute(r: Runnable): Unit
-
-  override def execute(runnable: Runnable): Unit = {
-    if (batchable(runnable)) { // If we can batch the runnable
-      _tasksLocal.get match {
-        case null => unbatchedExecute(new Batch(List(runnable))) // If we aren't in batching mode yet, enqueue batch
-        case some => _tasksLocal.set(runnable :: some) // If we are already in batching mode, add to batch
-      }
-    } else unbatchedExecute(runnable) // If not batchable, just delegate to underlying
-  }
-
-  /** Override this to define which runnables will be batched. */
-  def batchable(runnable: Runnable): Boolean = runnable match {
-    case _: OnCompleteRunnable => true
-    case _                     => false
-  }
-}
diff --git a/src/library/scala/concurrent/Future.scala b/src/library/scala/concurrent/Future.scala
index 36f3be341f..5a51e97072 100644
--- a/src/library/scala/concurrent/Future.scala
+++ b/src/library/scala/concurrent/Future.scala
@@ -675,11 +675,111 @@ object Future {
   // by just not ever using it itself. scala.concurrent
   // doesn't need to create defaultExecutionContext as
   // a side effect.
-  private[concurrent] object InternalCallbackExecutor extends ExecutionContext with BatchingExecutor {
-    override protected def unbatchedExecute(r: Runnable): Unit =
-      r.run()
+  private[concurrent] object InternalCallbackExecutor extends ExecutionContext with java.util.concurrent.Executor {
     override def reportFailure(t: Throwable): Unit =
       throw new IllegalStateException("problem in scala.concurrent internal callback", t)
+
+    /**
+     * The BatchingExecutor trait had to be inlined into InternalCallbackExecutor for binary compatibility.
+     *
+     * BatchingExecutor is a trait for an Executor
+     * which groups multiple nested `Runnable.run()` calls
+     * into a single Runnable passed to the original
+     * Executor. This can be a useful optimization
+     * because it bypasses the original context's task
+     * queue and keeps related (nested) code on a single
+     * thread which may improve CPU affinity. However,
+     * if tasks passed to the Executor are blocking
+     * or expensive, this optimization can prevent work-stealing
+     * and make performance worse. Also, some ExecutionContext
+     * may be fast enough natively that this optimization just
+     * adds overhead.
+     * The default ExecutionContext.global is already batching
+     * or fast enough not to benefit from it; while
+     * `fromExecutor` and `fromExecutorService` do NOT add
+     * this optimization since they don't know whether the underlying
+     * executor will benefit from it.
+     * A batching executor can create deadlocks if code does
+     * not use `scala.concurrent.blocking` when it should,
+     * because tasks created within other tasks will block
+     * on the outer task completing.
+     * This executor may run tasks in any order, including LIFO order.
+     * There are no ordering guarantees.
+     *
+     * WARNING: The underlying Executor's execute-method must not execute the submitted Runnable
+     * in the calling thread synchronously. It must enqueue/handoff the Runnable.
+     */
+    // invariant: if "_tasksLocal.get ne null" then we are inside BatchingRunnable.run; if it is null, we are outside
+    private val _tasksLocal = new ThreadLocal[List[Runnable]]()
+
+    private class Batch(val initial: List[Runnable]) extends Runnable with BlockContext {
+      private[this] var parentBlockContext: BlockContext = _
+      // this method runs in the delegate ExecutionContext's thread
+      override def run(): Unit = {
+        require(_tasksLocal.get eq null)
+
+        val prevBlockContext = BlockContext.current
+        BlockContext.withBlockContext(this) {
+          try {
+            parentBlockContext = prevBlockContext
+
+            @tailrec def processBatch(batch: List[Runnable]): Unit = batch match {
+              case Nil => ()
+              case head :: tail =>
+                _tasksLocal set tail
+                try {
+                  head.run()
+                } catch {
+                  case t: Throwable =>
+                    // if one task throws, move the
+                    // remaining tasks to another thread
+                    // so we can throw the exception
+                    // up to the invoking executor
+                    val remaining = _tasksLocal.get
+                    _tasksLocal set Nil
+                    unbatchedExecute(new Batch(remaining)) //TODO what if this submission fails?
+                    throw t // rethrow
+                }
+                processBatch(_tasksLocal.get) // since head.run() can add entries, always do _tasksLocal.get here
+            }
+
+            processBatch(initial)
+          } finally {
+            _tasksLocal.remove()
+            parentBlockContext = null
+          }
+        }
+      }
+
+      override def blockOn[T](thunk: => T)(implicit permission: CanAwait): T = {
+        // if we know there will be blocking, we don't want to keep tasks queued up because it could deadlock.
+        {
+          val tasks = _tasksLocal.get
+          _tasksLocal set Nil
+          if ((tasks ne null) && tasks.nonEmpty)
+            unbatchedExecute(new Batch(tasks))
+        }
+
+        // now delegate the blocking to the previous BC
+        require(parentBlockContext ne null)
+        parentBlockContext.blockOn(thunk)
+      }
+    }
+
+    override def execute(runnable: Runnable): Unit = runnable match {
+      // If we can batch the runnable
+      case _: OnCompleteRunnable =>
+        _tasksLocal.get match {
+          case null => unbatchedExecute(new Batch(List(runnable))) // If we aren't in batching mode yet, enqueue batch
+          case some => _tasksLocal.set(runnable :: some) // If we are already in batching mode, add to batch
+        }
+
+      // If not batchable, just delegate to underlying
+      case _ =>
+        unbatchedExecute(runnable)
+    }
+
+    private def unbatchedExecute(r: Runnable): Unit = r.run()
   }
 }
 
diff --git a/src/library/scala/concurrent/impl/ExecutionContextImpl.scala b/src/library/scala/concurrent/impl/ExecutionContextImpl.scala
index 77625e381c..43b437dbc6 100644
--- a/src/library/scala/concurrent/impl/ExecutionContextImpl.scala
+++ b/src/library/scala/concurrent/impl/ExecutionContextImpl.scala
@@ -25,7 +25,7 @@ private[scala] class ExecutionContextImpl private[impl] (es: Executor, reporter:
     case some => some
   }
 
-  private val uncaughtExceptionHandler: Thread.UncaughtExceptionHandler = new Thread.UncaughtExceptionHandler {
+  private[this] val uncaughtExceptionHandler: Thread.UncaughtExceptionHandler = new Thread.UncaughtExceptionHandler {
     def uncaughtException(thread: Thread, cause: Throwable): Unit = reporter(cause)
   }
 
@@ -96,11 +96,24 @@ private[scala] class ExecutionContextImpl private[impl] (es: Executor, reporter:
     }
   }
 
+
   def execute(runnable: Runnable): Unit = executor match {
     case fj: ForkJoinPool =>
       val fjt = runnable match {
         case t: ForkJoinTask[_] => t
-        case r => new ExecutionContextImpl.AdaptedForkJoinTask(r)
+        case runnable => new ForkJoinTask[Unit] {
+          final override def setRawResult(u: Unit): Unit = ()
+          final override def getRawResult(): Unit = ()
+          final override def exec(): Boolean = try { runnable.run(); true } catch {
+            case anything: Throwable ⇒
+              val t = Thread.currentThread
+              t.getUncaughtExceptionHandler match {
+                case null ⇒
+                case some ⇒ some.uncaughtException(t, anything)
+              }
+              throw anything
+          }
+        }
       }
       Thread.currentThread match {
         case fjw: ForkJoinWorkerThread if fjw.getPool eq fj => fjt.fork()
@@ -112,23 +125,7 @@ private[scala] class ExecutionContextImpl private[impl] (es: Executor, reporter:
   def reportFailure(t: Throwable) = reporter(t)
 }
 
-
 private[concurrent] object ExecutionContextImpl {
-
-  final class AdaptedForkJoinTask(runnable: Runnable) extends ForkJoinTask[Unit] {
-    final override def setRawResult(u: Unit): Unit = ()
-    final override def getRawResult(): Unit = ()
-    final override def exec(): Boolean = try { runnable.run(); true } catch {
-      case anything: Throwable ⇒
-        val t = Thread.currentThread
-        t.getUncaughtExceptionHandler match {
-          case null ⇒ 
-          case some ⇒ some.uncaughtException(t, anything)
-        }
-        throw anything
-    }
-  }
-
   def fromExecutor(e: Executor, reporter: Throwable => Unit = ExecutionContext.defaultReporter): ExecutionContextImpl = new ExecutionContextImpl(e, reporter)
   def fromExecutorService(es: ExecutorService, reporter: Throwable => Unit = ExecutionContext.defaultReporter): ExecutionContextImpl with ExecutionContextExecutorService =
     new ExecutionContextImpl(es, reporter) with ExecutionContextExecutorService {
diff --git a/src/library/scala/util/Random.scala b/src/library/scala/util/Random.scala
index 2b11594f66..24c4cd7a32 100644
--- a/src/library/scala/util/Random.scala
+++ b/src/library/scala/util/Random.scala
@@ -17,7 +17,7 @@ import scala.language.{implicitConversions, higherKinds}
  *  @author Stephane Micheloud
  *
  */
-class Random(val self: java.util.Random) extends AnyRef with Serializable {
+class Random(val self: java.util.Random) {
   /** Creates a new random number generator using a single long seed. */
   def this(seed: Long) = this(new java.util.Random(seed))
 
diff --git a/src/reflect/scala/reflect/internal/PrivateWithin.scala b/src/reflect/scala/reflect/internal/PrivateWithin.scala
deleted file mode 100644
index 9b99b94b41..0000000000
--- a/src/reflect/scala/reflect/internal/PrivateWithin.scala
+++ /dev/null
@@ -1,23 +0,0 @@
-package scala.reflect
-package internal
-
-import ClassfileConstants._
-
-trait PrivateWithin {
-  self: SymbolTable =>
-
-  def importPrivateWithinFromJavaFlags(sym: Symbol, jflags: Int): Symbol = {
-    if ((jflags & (JAVA_ACC_PRIVATE | JAVA_ACC_PROTECTED | JAVA_ACC_PUBLIC)) == 0)
-      // See ticket #1687 for an example of when topLevelClass is NoSymbol: it
-      // apparently occurs when processing v45.3 bytecode.
-      if (sym.enclosingTopLevelClass != NoSymbol)
-        sym.privateWithin = sym.enclosingTopLevelClass.owner
-
-    // protected in java means package protected. #3946
-    if ((jflags & JAVA_ACC_PROTECTED) != 0)
-      if (sym.enclosingTopLevelClass != NoSymbol)
-        sym.privateWithin = sym.enclosingTopLevelClass.owner
-
-    sym
-  }
-}
\ No newline at end of file
diff --git a/src/reflect/scala/reflect/internal/SymbolTable.scala b/src/reflect/scala/reflect/internal/SymbolTable.scala
index f75855f1ec..5ccf81b4b5 100644
--- a/src/reflect/scala/reflect/internal/SymbolTable.scala
+++ b/src/reflect/scala/reflect/internal/SymbolTable.scala
@@ -38,7 +38,6 @@ abstract class SymbolTable extends macros.Universe
                               with StdAttachments
                               with StdCreators
                               with BuildUtils
-                              with PrivateWithin
 {
 
   val gen = new TreeGen { val global: SymbolTable.this.type = SymbolTable.this }
@@ -352,6 +351,21 @@ abstract class SymbolTable extends macros.Universe
    */
   implicit val StringContextStripMarginOps: StringContext => StringContextStripMarginOps = util.StringContextStripMarginOps
 
+  def importPrivateWithinFromJavaFlags(sym: Symbol, jflags: Int): Symbol = {
+    import ClassfileConstants._
+    if ((jflags & (JAVA_ACC_PRIVATE | JAVA_ACC_PROTECTED | JAVA_ACC_PUBLIC)) == 0)
+      // See ticket #1687 for an example of when topLevelClass is NoSymbol: it
+      // apparently occurs when processing v45.3 bytecode.
+      if (sym.enclosingTopLevelClass != NoSymbol)
+        sym.privateWithin = sym.enclosingTopLevelClass.owner
+
+    // protected in java means package protected. #3946
+    if ((jflags & JAVA_ACC_PROTECTED) != 0)
+      if (sym.enclosingTopLevelClass != NoSymbol)
+        sym.privateWithin = sym.enclosingTopLevelClass.owner
+
+    sym
+  }
 }
 
 object SymbolTableStats {
diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
index 778c826dc0..3442e3d22e 100644
--- a/src/reflect/scala/reflect/runtime/JavaMirrors.scala
+++ b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
@@ -574,7 +574,7 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
               case None =>
                 // class does not have a Scala signature; it's a Java class
                 info("translating reflection info for Java " + jclazz) //debug
-                initClassAndModule(clazz, module, new FromJavaClassCompleter(clazz, module, jclazz))
+                initClassModule(clazz, module, new FromJavaClassCompleter(clazz, module, jclazz))
             }
         }
       } catch {
@@ -686,9 +686,9 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
         def enter(sym: Symbol, mods: Int) =
           (if (jModifier.isStatic(mods)) module.moduleClass else clazz).info.decls enter sym
 
-        for (jinner <- jclazz.getDeclaredClasses)
-          jclassAsScala(jinner) // inner class is entered as a side-effect
-                                // no need to call enter explicitly
+        for (jinner <- jclazz.getDeclaredClasses) {
+          enter(jclassAsScala(jinner, clazz), jinner.getModifiers)
+        }
 
         pendingLoadActions = { () =>
 
@@ -1046,14 +1046,14 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
      *  @param jclazz  The Java class
      *  @return A Scala class symbol that wraps all reflection info of `jclazz`
      */
-    private def jclassAsScala(jclazz: jClass[_]): ClassSymbol =
-      toScala(classCache, jclazz)(_ jclassAsScala1 _)
+    private def jclassAsScala(jclazz: jClass[_]): Symbol = jclassAsScala(jclazz, sOwner(jclazz))
 
-    private def jclassAsScala1(jclazz: jClass[_]): ClassSymbol = {
-      val owner = sOwner(jclazz)
+    private def jclassAsScala(jclazz: jClass[_], owner: Symbol): ClassSymbol = {
       val name = scalaSimpleName(jclazz)
       val completer = (clazz: Symbol, module: Symbol) => new FromJavaClassCompleter(clazz, module, jclazz)
-      initAndEnterClassAndModule(owner, name, completer)._1
+      val (clazz, module) = createClassModule(owner, name, completer)
+      classCache enter (jclazz, clazz)
+      clazz
     }
 
     /**
diff --git a/src/reflect/scala/reflect/runtime/SymbolLoaders.scala b/src/reflect/scala/reflect/runtime/SymbolLoaders.scala
index 311db64b91..61663f6181 100644
--- a/src/reflect/scala/reflect/runtime/SymbolLoaders.scala
+++ b/src/reflect/scala/reflect/runtime/SymbolLoaders.scala
@@ -57,7 +57,7 @@ private[reflect] trait SymbolLoaders { self: SymbolTable =>
    *  @param name    The simple name of the newly created class
    *  @param completer  The completer to be used to set the info of the class and the module
    */
-  protected def initAndEnterClassAndModule(owner: Symbol, name: TypeName, completer: (Symbol, Symbol) => LazyType) = {
+  protected def createClassModule(owner: Symbol, name: TypeName, completer: (Symbol, Symbol) => LazyType) = {
     assert(!(name.toString endsWith "[]"), name)
     val clazz = owner.newClass(name)
     val module = owner.newModule(name.toTermName)
@@ -67,7 +67,7 @@ private[reflect] trait SymbolLoaders { self: SymbolTable =>
       owner.info.decls enter clazz
       owner.info.decls enter module
     }
-    initClassAndModule(clazz, module, completer(clazz, module))
+    initClassModule(clazz, module, completer(clazz, module))
     (clazz, module)
   }
 
@@ -75,7 +75,7 @@ private[reflect] trait SymbolLoaders { self: SymbolTable =>
     List(clazz, module, module.moduleClass) foreach (_ setInfo info)
   }
 
-  protected def initClassAndModule(clazz: Symbol, module: Symbol, completer: LazyType) =
+  protected def initClassModule(clazz: Symbol, module: Symbol, completer: LazyType) =
     setAllInfos(clazz, module, completer)
 
   /** The type completer for packages.
@@ -118,7 +118,7 @@ private[reflect] trait SymbolLoaders { self: SymbolTable =>
             val loadingMirror = currentMirror.mirrorDefining(cls)
             val (clazz, module) =
               if (loadingMirror eq currentMirror) {
-                initAndEnterClassAndModule(pkgClass, name.toTypeName, new TopClassCompleter(_, _))
+                createClassModule(pkgClass, name.toTypeName, new TopClassCompleter(_, _))
               } else {
                 val origOwner = loadingMirror.packageNameToScala(pkgClass.fullName)
                 val clazz = origOwner.info decl name.toTypeName