Merge remote-tracking branch 'origin/2.10.x' into pr/merge-2.10

* origin/2.10.x:
  SI-6969, mishandling of SoftReferences in method cache.
  SI-7011 Fix finding constructor type in captured var definitions
  SI-6987 Tests fsc verbose output
  SI-6987 Fixes fsc compile server verbose output
  SI-6231 Report unsupported free var capture by a trait.
  SI-6666 Restrict hidden `this` access in self/super calls.
  SI-6902 Check unreachability under @unchecked
  SI-6976 Fix value class separate compilation crasher.
  Closes SI-6952: add correct error positions for Dynamic feature check.

Conflicts:
	src/compiler/scala/tools/nsc/CompileServer.scala
	src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala

21 files changed, 388 insertions, 2 deletions

diff --git a/test/files/neg/t6040.check b/test/files/neg/t6040.check
index f6757f97e3..f91df0c46d 100644
--- a/test/files/neg/t6040.check
+++ b/test/files/neg/t6040.check
@@ -1,7 +1,9 @@
-error: extension of type scala.Dynamic needs to be enabled
+t6040.scala:1: error: extension of type scala.Dynamic needs to be enabled
 by making the implicit value language.dynamics visible.
 This can be achieved by adding the import clause 'import scala.language.dynamics'
 or by setting the compiler option -language:dynamics.
 See the Scala docs for value scala.language.dynamics for a discussion
 why the feature needs to be explicitly enabled.
+class X extends Dynamic
+                ^
 one error found
diff --git a/test/files/neg/t6231.check b/test/files/neg/t6231.check
new file mode 100644
index 0000000000..b27961d393
--- /dev/null
+++ b/test/files/neg/t6231.check
@@ -0,0 +1,6 @@
+t6231.scala:4: error: Implementation restriction: local trait Bug$X$1 is unable to automatically capture the
+free variable value ev$1 on behalf of anonymous class anonfun$qux$1. You can manually assign it to a val inside the trait,
+and refer that that val in anonymous class anonfun$qux$1. For more details, see SI-6231.
+      def qux = { () => ev }
+                        ^
+one error found
diff --git a/test/files/neg/t6231.scala b/test/files/neg/t6231.scala
new file mode 100644
index 0000000000..1e5b4e0e1a
--- /dev/null
+++ b/test/files/neg/t6231.scala
@@ -0,0 +1,15 @@
+object Bug {
+  def bar(ev: Any) = {
+    trait X {
+      def qux = { () => ev }
+    }
+    new X {}.qux()
+
+    // workaround
+    trait Y {
+      val ev2 = ev // manually capture `ev` so that `ev2` is added to the trait interface.
+      def qux = { () => ev2 }
+    }
+  }
+}
+
diff --git a/test/files/neg/t6666.check b/test/files/neg/t6666.check
new file mode 100644
index 0000000000..d0378173ea
--- /dev/null
+++ b/test/files/neg/t6666.check
@@ -0,0 +1,40 @@
+t6666.scala:23: error: Implementation restriction: access of method x$2 in object O1 from anonymous class 2, would require illegal premature access to object O1
+  F.byname(x)
+           ^
+t6666.scala:30: error: Implementation restriction: access of value x$3 in object O2 from anonymous class 3, would require illegal premature access to object O2
+  F.byname(x)
+           ^
+t6666.scala:37: error: Implementation restriction: access of method x$4 in object O3 from anonymous class 4, would require illegal premature access to object O3
+  F.hof(() => x)
+              ^
+t6666.scala:50: error: Implementation restriction: access of method x$6 in class C1 from anonymous class 7, would require illegal premature access to the unconstructed `this` of class C1
+  F.byname(x)
+           ^
+t6666.scala:54: error: Implementation restriction: access of value x$7 in class C2 from anonymous class 8, would require illegal premature access to the unconstructed `this` of class C2
+  F.byname(x)
+           ^
+t6666.scala:58: error: Implementation restriction: access of method x$8 in class C3 from anonymous class 9, would require illegal premature access to the unconstructed `this` of class C3
+  F.hof(() => x)
+              ^
+t6666.scala:62: error: Implementation restriction: access of method x$9 in class C4 from object Nested$5, would require illegal premature access to the unconstructed `this` of class C4
+  object Nested { def xx = x}
+                           ^
+t6666.scala:68: error: Implementation restriction: access of method x$10 in class C5 from object Nested$6, would require illegal premature access to the unconstructed `this` of class C5
+    object Nested { def xx = x}
+                             ^
+t6666.scala:83: error: Implementation restriction: access of method x$12 in class C11 from anonymous class 12, would require illegal premature access to the unconstructed `this` of class C11
+      F.byname(x)
+               ^
+t6666.scala:102: error: Implementation restriction: access of method x$13 in class C13 from anonymous class 13, would require illegal premature access to the unconstructed `this` of class C13
+      F.hof(() => x)
+                  ^
+t6666.scala:111: error: Implementation restriction: access of method x$14 in class C14 from object Nested$7, would require illegal premature access to the unconstructed `this` of class C14
+      object Nested { def xx = x}
+                               ^
+t6666.scala:122: error: Implementation restriction: access of method x$15 in class C15 from object Nested$8, would require illegal premature access to the unconstructed `this` of class C15
+        object Nested { def xx = x}
+                                 ^
+t6666.scala:131: error: Implementation restriction: access of method foo$1 in class COuter from class CInner$1, would require illegal premature access to the unconstructed `this` of class COuter
+  class CInner extends C({foo})
+                          ^
+13 errors found
diff --git a/test/files/neg/t6666.scala b/test/files/neg/t6666.scala
new file mode 100644
index 0000000000..d37ffaf141
--- /dev/null
+++ b/test/files/neg/t6666.scala
@@ -0,0 +1,132 @@
+class C(a: Any)
+object F {
+  def byname(a: => Any) = println(a)
+  def hof(a: () => Any) = println(a())
+}
+
+class COkay extends C(0) {
+  def this(a: Any) {
+    this()
+    def x = "".toString
+    F.byname(x)
+  }
+}
+
+//
+// The thunk's apply method accesses the MODULE$
+// field before it is set.
+//
+//   0: getstatic #23; //Field O1$.MODULE$:LO1$;
+//   3: invokevirtual #26; //Method O1$.O1$$x$1:()Ljava/lang/String;
+object O1 extends C({
+  def x = "".toString
+  F.byname(x)
+})
+
+// java.lang.NullPointerException
+//   at O2$$anonfun$$init$$1.apply(<console>:11)
+object O2 extends C({
+  lazy val x = "".toString
+  F.byname(x)
+})
+
+// java.lang.NullPointerException
+//   at O3$$anonfun$$init$$1.apply(<console>:11)
+object O3 extends C({
+  def x = "".toString
+  F.hof(() => x)
+})
+
+// Okay, the nested classes don't get an outer pointer passed,
+// just an extra param for `x: String`.
+object O6 extends C({
+  val x = "".toString
+  F.byname(x); F.hof(() => x); (new { val xx = x }.xx)
+})
+
+
+class C1 extends C({
+  def x = "".toString
+  F.byname(x)
+})
+class C2 extends C({
+  lazy val x = "".toString
+  F.byname(x)
+})
+class C3 extends C({
+  def x = "".toString
+  F.hof(() => x)
+})
+class C4 extends C({
+  def x = "".toString
+  object Nested { def xx = x}
+  Nested.xx
+})
+class C5 extends C({
+  def x = "".toString
+  val y = {
+    object Nested { def xx = x}
+    Nested.xx
+  }
+})
+
+// okay, for same reason as O6
+class C6 extends C({
+  val x = "".toString
+  F.byname(x); F.hof(() => x); (new { val xx = x }.xx)
+})
+
+class C11(a: Any) {
+  def this() = {
+    this({
+     def x = "".toString
+      F.byname(x)
+    })
+  }
+}
+
+// Crashes earlier in lazyVals.
+// class C12(a: Any) {
+//   def this() = {
+//     this({
+//       lazy val x = "".toString
+//       F.byname(x)
+//     })
+//   }
+// }
+
+class C13(a: Any) {
+  def this() = {
+    this({
+      def x = "".toString
+      F.hof(() => x)
+    })
+  }
+}
+
+class C14(a: Any) {
+  def this() = {
+    this({
+      def x = "".toString
+      object Nested { def xx = x}
+      Nested.xx
+    })
+  }
+}
+
+class C15(a: Any) {
+  def this() = {
+    this({
+      def x = "".toString
+      val y = {
+        object Nested { def xx = x}
+        Nested.xx
+      }
+    })
+  }
+}
+
+class COuter extends C({
+  def foo = 0
+  class CInner extends C({foo})
+})
\ No newline at end of file
diff --git a/test/files/neg/t6902.check b/test/files/neg/t6902.check
new file mode 100644
index 0000000000..ed0ed75303
--- /dev/null
+++ b/test/files/neg/t6902.check
@@ -0,0 +1,12 @@
+t6902.scala:4: warning: unreachable code
+    case Some(b) => 3 // no warning was emitted
+                    ^
+t6902.scala:9: warning: unreachable code
+    case Some(b) => 3 // no warning was emitted
+                    ^
+t6902.scala:21: warning: unreachable code
+    case 1 => 3 // crash
+              ^
+error: No warnings can be incurred under -Xfatal-warnings.
+three warnings found
+one error found
diff --git a/test/files/neg/t6902.flags b/test/files/neg/t6902.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t6902.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t6902.scala b/test/files/neg/t6902.scala
new file mode 100644
index 0000000000..ce5ff8b6fb
--- /dev/null
+++ b/test/files/neg/t6902.scala
@@ -0,0 +1,23 @@
+object Test {
+  Some(Some(1)) collect {
+    case Some(a) => 2
+    case Some(b) => 3 // no warning was emitted
+  }
+
+  (Some(1): @ unchecked) match {
+    case Some(a) => 2
+    case Some(b) => 3 // no warning was emitted
+  }
+
+  // A variation of SI-6011, which eluded the fix
+  // in 2.10.0.
+  //
+  // duplicate keys in SWITCH, can't pick arbitrarily one of them to evict, see SI-6011.
+  // at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:50)
+  // at scala.tools.nsc.Global.abort(Global.scala:249)
+  // at scala.tools.nsc.backend.jvm.GenASM$JPlainBuilder$jcode$.emitSWITCH(GenASM.scala:1850)
+  ((1: Byte): @unchecked @annotation.switch) match {
+    case 1 => 2
+    case 1 => 3 // crash
+  }
+}
diff --git a/test/files/neg/t6952.check b/test/files/neg/t6952.check
new file mode 100644
index 0000000000..f1e1881404
--- /dev/null
+++ b/test/files/neg/t6952.check
@@ -0,0 +1,13 @@
+t6952.scala:2: error: extension of type scala.Dynamic needs to be enabled
+by making the implicit value language.dynamics visible.
+This can be achieved by adding the import clause 'import scala.language.dynamics'
+or by setting the compiler option -language:dynamics.
+See the Scala docs for value scala.language.dynamics for a discussion
+why the feature needs to be explicitly enabled.
+trait B extends Dynamic
+                ^
+t6952.scala:3: error: extension of type scala.Dynamic needs to be enabled
+by making the implicit value language.dynamics visible.
+trait C extends A with Dynamic
+                       ^
+two errors found
diff --git a/test/files/neg/t6952.scala b/test/files/neg/t6952.scala
new file mode 100644
index 0000000000..257ea3be68
--- /dev/null
+++ b/test/files/neg/t6952.scala
@@ -0,0 +1,4 @@
+trait A
+trait B extends Dynamic
+trait C extends A with Dynamic
+trait D extends B
diff --git a/test/files/pos/t6976/Exts_1.scala b/test/files/pos/t6976/Exts_1.scala
new file mode 100644
index 0000000000..9b3a69edd9
--- /dev/null
+++ b/test/files/pos/t6976/Exts_1.scala
@@ -0,0 +1,10 @@
+object Exts {
+  implicit class AnyExts[T](val o: T) extends AnyVal {
+    def moo = "moo!"
+  }
+}
+
+trait Exts {
+  import language.implicitConversions
+  implicit def AnyExts[T](o: T) = Exts.AnyExts(o)
+}
diff --git a/test/files/pos/t6976/ImplicitBug_1.scala b/test/files/pos/t6976/ImplicitBug_1.scala
new file mode 100644
index 0000000000..c9031bab2e
--- /dev/null
+++ b/test/files/pos/t6976/ImplicitBug_1.scala
@@ -0,0 +1,27 @@
+// This one is weird and nasty. Not sure if this is scalac or sbt 
+// (tried with 0.12 & 0.12.2-RC2) bug.
+//
+// A level of indirection is required to trigger this bug.
+// Exts seems to need to be defined in separate file.
+//
+// Steps to reproduce:
+// 1. sbt clean
+// 2. sbt run (it works)
+// 3. Comment A & uncomment B.
+// 4. sbt run (it fails)
+// 5. Switch it back & sbt run. It still fails.
+//
+// In this project sbt clean helps. However in a large project where this 
+// bug was found compiler crashed even after doing sbt clean. The only
+// way to work around this was to reference Exts object explicitly (C) in 
+// the source file using its implicit classes.
+
+// Lets suppose this is a mega-trait combining all sorts of helper 
+// functionality.
+trait Support extends Exts
+
+object ImplicitsBug extends App with Support { // A
+// object ImplicitsBug extends App with Exts { // B
+  //Exts // C) this reference helped in the large project.
+  println(3.moo)
+}
diff --git a/test/files/pos/t6976/ImplicitBug_2.scala b/test/files/pos/t6976/ImplicitBug_2.scala
new file mode 100644
index 0000000000..2fea5e2993
--- /dev/null
+++ b/test/files/pos/t6976/ImplicitBug_2.scala
@@ -0,0 +1,7 @@
+trait Support extends Exts
+
+// object ImplicitsBug extends App with Support { // A
+object ImplicitsBug extends App with Exts { // B
+  //Exts // C) this reference helped in the large project.
+  println(3.moo)
+}
diff --git a/test/files/pos/t7011.flags b/test/files/pos/t7011.flags
new file mode 100644
index 0000000000..a4c161553e
--- /dev/null
+++ b/test/files/pos/t7011.flags
@@ -0,0 +1 @@
+-Ydebug -Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/pos/t7011.scala b/test/files/pos/t7011.scala
new file mode 100644
index 0000000000..539f662bc0
--- /dev/null
+++ b/test/files/pos/t7011.scala
@@ -0,0 +1,7 @@
+object bar {
+	def foo {
+    lazy val x = 42
+
+    {()=>x}
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/t6011c.scala b/test/files/run/t6011c.scala
new file mode 100644
index 0000000000..0647e3f81a
--- /dev/null
+++ b/test/files/run/t6011c.scala
@@ -0,0 +1,13 @@
+object Test extends App {
+  // A variation of SI-6011, which eluded the fix
+  // in 2.10.0.
+  //
+  // duplicate keys in SWITCH, can't pick arbitrarily one of them to evict, see SI-6011.
+  // at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:50)
+  // at scala.tools.nsc.Global.abort(Global.scala:249)
+  // at scala.tools.nsc.backend.jvm.GenASM$JPlainBuilder$jcode$.emitSWITCH(GenASM.scala:1850)
+  ((1: Byte): @unchecked @annotation.switch) match {
+    case 1 => 2
+    case 1 => 3 // crash
+  }
+}
diff --git a/test/files/run/t6028.check b/test/files/run/t6028.check
index 42921ae2f5..942f3d5f0c 100644
--- a/test/files/run/t6028.check
+++ b/test/files/run/t6028.check
@@ -15,7 +15,7 @@ package <empty> {
       }
     };
     def bar(barParam: Int): Object = {
-      @volatile var MethodLocalObject$module: runtime.VolatileObjectRef = new runtime.VolatileObjectRef(<empty>);
+      @volatile var MethodLocalObject$module: runtime.VolatileObjectRef = new runtime.VolatileObjectRef(null);
       T.this.MethodLocalObject$1(barParam, MethodLocalObject$module)
     };
     def tryy(tryyParam: Int): Function0 = {
diff --git a/test/files/run/t6969.check b/test/files/run/t6969.check
new file mode 100644
index 0000000000..78297812c9
--- /dev/null
+++ b/test/files/run/t6969.check
@@ -0,0 +1 @@
+All threads completed.
diff --git a/test/files/run/t6969.scala b/test/files/run/t6969.scala
new file mode 100644
index 0000000000..8cfc28c1e5
--- /dev/null
+++ b/test/files/run/t6969.scala
@@ -0,0 +1,28 @@
+object Test {
+  private type Clearable = { def clear(): Unit }
+  private def choke() = {
+    try new Array[Object]((Runtime.getRuntime().maxMemory min Int.MaxValue).toInt)
+    catch {
+      case _: OutOfMemoryError => // what do you mean, out of memory?
+      case t: Throwable        => println(t)
+    }
+  }
+  private def f(x: Clearable) = x.clear()
+  class Choker(id: Int) extends Thread {
+    private def g(iteration: Int) = {
+      val map = scala.collection.mutable.Map[Int, Int](1 -> 2)
+      try f(map) catch { case t: NullPointerException => println(s"Failed at $id/$iteration") ; throw t }
+      choke()
+    }
+    override def run() {
+      1 to 50 foreach g
+    }
+  }
+
+  def main(args: Array[String]): Unit = {
+    val threads = 1 to 3 map (id => new Choker(id))
+    threads foreach (_.start())
+    threads foreach (_.join())
+    println("All threads completed.")
+  }
+}
diff --git a/test/files/run/t6987.check b/test/files/run/t6987.check
new file mode 100644
index 0000000000..86fc96c679
--- /dev/null
+++ b/test/files/run/t6987.check
@@ -0,0 +1 @@
+got successful verbose results!
diff --git a/test/files/run/t6987.scala b/test/files/run/t6987.scala
new file mode 100644
index 0000000000..37e91d61ae
--- /dev/null
+++ b/test/files/run/t6987.scala
@@ -0,0 +1,43 @@
+import java.io._
+import tools.nsc.{CompileClient, CompileServer}
+import java.util.concurrent.{CountDownLatch, TimeUnit}
+
+object Test extends App {
+  val startupLatch = new CountDownLatch(1)
+  // we have to explicitly launch our server because when the client launches a server it uses 
+  // the "scala" shell command meaning whatever version of scala (and whatever version of libraries)
+  // happens to be in the path gets used
+  val t = new Thread(new Runnable {
+    def run() = {
+      CompileServer.execute(() => startupLatch.countDown(), Array[String]())
+    }
+  })
+  t setDaemon true
+  t.start()
+  if (!startupLatch.await(2, TimeUnit.MINUTES))
+    sys error "Timeout waiting for server to start"
+
+  val baos = new ByteArrayOutputStream()
+  val ps = new PrintStream(baos) 
+
+  val success = (scala.Console withOut ps) {
+    // shut down the server via the client using the verbose flag
+    CompileClient.process(Array("-shutdown", "-verbose"))
+  }
+
+  // now make sure we got success and a verbose result
+  val msg = baos.toString()
+
+  if (success) {
+    if (msg contains "Settings after normalizing paths") {
+     println("got successful verbose results!")
+    } else {
+     println("did not get the string expected, full results were:")
+     println(msg)
+    }
+  } else {
+    println("got a failure. Full results were:")
+    println(msg)
+  }
+  scala.Console.flush
+}