addresses pull request feedback

14 files changed, 30 insertions, 21 deletions

diff --git a/src/compiler/scala/reflect/macros/contexts/Enclosures.scala b/src/compiler/scala/reflect/macros/contexts/Enclosures.scala
index 0b4aad85a3..5e931817b5 100644
--- a/src/compiler/scala/reflect/macros/contexts/Enclosures.scala
+++ b/src/compiler/scala/reflect/macros/contexts/Enclosures.scala
@@ -18,7 +18,6 @@ trait Enclosures {
   // vals are eager to simplify debugging
   // after all we wouldn't save that much time by making them lazy
   val macroApplication: Tree                      = expandee
-  val enclosingOwner                              = site.owner
   def enclosingPackage: PackageDef                = strictEnclosure[PackageDef]
   val enclosingClass: Tree                        = lenientEnclosure[ImplDef]
   def enclosingImpl: ImplDef                      = strictEnclosure[ImplDef]
diff --git a/src/compiler/scala/reflect/macros/contexts/Internals.scala b/src/compiler/scala/reflect/macros/contexts/Internals.scala
index e35a8ae034..cca6d957da 100644
--- a/src/compiler/scala/reflect/macros/contexts/Internals.scala
+++ b/src/compiler/scala/reflect/macros/contexts/Internals.scala
@@ -7,6 +7,8 @@ trait Internals extends scala.tools.nsc.transform.TypingTransformers {
   import global._
 
   lazy val internal: ContextInternalApi = new global.SymbolTableInternal with ContextInternalApi {
+    val enclosingOwner = callsiteTyper.context.owner
+
     class HofTransformer(hof: (Tree, TransformApi) => Tree) extends Transformer {
       val api = new TransformApi {
         def recur(tree: Tree): Tree = hof(tree, this)
diff --git a/src/compiler/scala/reflect/macros/contexts/Typers.scala b/src/compiler/scala/reflect/macros/contexts/Typers.scala
index 0c3881fdcf..f1620b764b 100644
--- a/src/compiler/scala/reflect/macros/contexts/Typers.scala
+++ b/src/compiler/scala/reflect/macros/contexts/Typers.scala
@@ -12,6 +12,7 @@ trait Typers {
   val TypecheckMode = scala.reflect.internal.Mode
   val TERMmode = TypecheckMode.EXPRmode
   val TYPEmode = TypecheckMode.TYPEmode | TypecheckMode.FUNmode
+  val PATTERNmode = TypecheckMode.PATTERNmode
 
   /**
    * @see [[scala.tools.reflect.ToolBox.typeCheck]]
diff --git a/src/compiler/scala/tools/reflect/ToolBox.scala b/src/compiler/scala/tools/reflect/ToolBox.scala
index f47db49718..dfe53be6c9 100644
--- a/src/compiler/scala/tools/reflect/ToolBox.scala
+++ b/src/compiler/scala/tools/reflect/ToolBox.scala
@@ -23,7 +23,7 @@ trait ToolBox[U <: scala.reflect.api.Universe] {
 
   /** Represents mode of operations of the typechecker underlying `c.typecheck` calls.
    *  Is necessary since the shape of the typechecked tree alone is not enough to guess how it should be typechecked.
-   *  Can be EXPRmode (typecheck as a term) or TYPEmode (typecheck as a type).
+   *  Can be EXPRmode (typecheck as a term), TYPEmode (typecheck as a type) or PATTERNmode (typecheck as a pattern).
    */
   type TypecheckMode
 
@@ -36,6 +36,10 @@ trait ToolBox[U <: scala.reflect.api.Universe] {
    */
   val TYPEmode: TypecheckMode
 
+  /** Indicates that an argument to `c.typecheck` should be typechecked as a pattern.
+   */
+  val PATTERNmode: TypecheckMode
+
   /** @see `Typers.typecheck`
    */
   @deprecated("Use `tb.typecheck` instead", "2.11.0")
diff --git a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
index 3cae6fa8a8..3a40b44c74 100644
--- a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
+++ b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
@@ -365,6 +365,7 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf =>
     val TypecheckMode = scala.reflect.internal.Mode
     val TERMmode = TypecheckMode.EXPRmode
     val TYPEmode = TypecheckMode.TYPEmode | TypecheckMode.FUNmode
+    val PATTERNmode = TypecheckMode.PATTERNmode
 
     def typecheck(tree: u.Tree, mode: TypecheckMode = TERMmode, expectedType: u.Type, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): u.Tree = withCompilerApi { compilerApi =>
       import compilerApi._
diff --git a/src/compiler/scala/tools/reflect/quasiquotes/Placeholders.scala b/src/compiler/scala/tools/reflect/quasiquotes/Placeholders.scala
index f50d699e22..29df0ae670 100644
--- a/src/compiler/scala/tools/reflect/quasiquotes/Placeholders.scala
+++ b/src/compiler/scala/tools/reflect/quasiquotes/Placeholders.scala
@@ -42,7 +42,7 @@ trait Placeholders { self: Quasiquotes =>
       case nme.apply   => args
       case nme.unapply =>
         val (dummy @ Ident(nme.SELECTOR_DUMMY)) :: Nil = args
-        internal.subpatterns(dummy)
+        internal.subpatterns(dummy).get
       case _           => global.abort("unreachable")
     }
 
diff --git a/src/reflect/scala/reflect/api/FlagSets.scala b/src/reflect/scala/reflect/api/FlagSets.scala
index f36056cc3b..3d438e5b2f 100644
--- a/src/reflect/scala/reflect/api/FlagSets.scala
+++ b/src/reflect/scala/reflect/api/FlagSets.scala
@@ -176,9 +176,8 @@ trait FlagSets { self: Universe =>
     val ENUM: FlagSet
 
     /** Flag indicating that tree represents a parameter of the primary constructor of some class
-     *  or a synthetic member underlying thereof:
+     *  or a synthetic member underlying thereof. E.g. here's how 'class C(val x: Int)' is represented:
      *
-     *      13:57 ~$ parse 'class C(val x: Int)'
      *      [[syntax trees at end of parser]]// Scala source: tmposDU52
      *      class C extends scala.AnyRef {
      *        <paramaccessor> val x: Int = _;
@@ -202,9 +201,8 @@ trait FlagSets { self: Universe =>
     val PARAMACCESSOR: FlagSet
 
     /** Flag indicating that tree represents a parameter of the primary constructor of some case class
-     *  or a synthetic member underlying thereof:
+     *  or a synthetic member underlying thereof.  E.g. here's how 'case class C(val x: Int)' is represented:
      *
-     *      13:58 ~$ parse 'case class C(val x: Int)'
      *      [[syntax trees at end of parser]]// Scala source: tmpnHkJ3y
      *      case class C extends scala.Product with scala.Serializable {
      *        <caseaccessor> <paramaccessor> val x: Int = _;
diff --git a/src/reflect/scala/reflect/internal/Internals.scala b/src/reflect/scala/reflect/internal/Internals.scala
index a152787ae1..ad0bcef48d 100644
--- a/src/reflect/scala/reflect/internal/Internals.scala
+++ b/src/reflect/scala/reflect/internal/Internals.scala
@@ -122,7 +122,7 @@ trait Internals extends api.Internals {
     def typeBounds(lo: Type, hi: Type): TypeBounds = self.TypeBounds(lo, hi)
     def boundedWildcardType(bounds: TypeBounds): BoundedWildcardType = self.BoundedWildcardType(bounds)
 
-    def subpatterns(tree: Tree): List[Tree] = tree.attachments.get[SubpatternsAttachment].get.patterns
+    def subpatterns(tree: Tree): Option[List[Tree]] = tree.attachments.get[SubpatternsAttachment].map(_.patterns.map(_.duplicate))
   }
 
   lazy val treeBuild = new self.TreeGen {
diff --git a/src/reflect/scala/reflect/macros/Enclosures.scala b/src/reflect/scala/reflect/macros/Enclosures.scala
index 7c186139cf..69ede42cc7 100644
--- a/src/reflect/scala/reflect/macros/Enclosures.scala
+++ b/src/reflect/scala/reflect/macros/Enclosures.scala
@@ -20,7 +20,7 @@ import scala.language.existentials // SI-6541
  *  This is somewhat aligned with the overall evolution of macros during the 2.11 development cycle, where we played with
  *  `c.introduceTopLevel` and `c.introduceMember`, but at the end of the day decided to reject them.
  *
- *  If you're relying on the now deprecated APIs, consider using the new [[c.enclosingOwner]] method that can be used to obtain
+ *  If you're relying on the now deprecated APIs, consider using the new [[c.internal.enclosingOwner]] method that can be used to obtain
  *  the names of enclosing definitions. Alternatively try reformulating your macros in terms of completely local expansion
  *  and/or joining a discussion of a somewhat related potential language feature at [[https://groups.google.com/forum/#!topic/scala-debate/f4CLmYShX6Q]].
  *  We also welcome questions and suggestions on our mailing lists, where we would be happy to further discuss this matter.
@@ -52,11 +52,6 @@ trait Enclosures {
    */
   def enclosingPosition: Position
 
-  /** Symbol associated with the innermost enclosing lexical context.
-   *  Walking the owner chain of this symbol will reveal information about more and more enclosing contexts.
-   */
-  def enclosingOwner: Symbol
-
   /** Tree that corresponds to the enclosing method, or EmptyTree if not applicable.
    *  @see [[scala.reflect.macros.Enclosures]]
    */
diff --git a/src/reflect/scala/reflect/macros/Internals.scala b/src/reflect/scala/reflect/macros/Internals.scala
index 415e70c36e..843644b7e3 100644
--- a/src/reflect/scala/reflect/macros/Internals.scala
+++ b/src/reflect/scala/reflect/macros/Internals.scala
@@ -14,6 +14,11 @@ trait Internals {
 
   /** @see [[scala.reflect.api.Internals]] */
   trait ContextInternalApi extends universe.MacroInternalApi {
+    /** Symbol associated with the innermost enclosing lexical context.
+     *  Walking the owner chain of this symbol will reveal information about more and more enclosing contexts.
+     */
+    def enclosingOwner: Symbol
+
     /** Functions that are available during [[transform]].
      *  @see [[transform]]
      */
diff --git a/src/reflect/scala/reflect/macros/Typers.scala b/src/reflect/scala/reflect/macros/Typers.scala
index f1d8575774..d0dccb469d 100644
--- a/src/reflect/scala/reflect/macros/Typers.scala
+++ b/src/reflect/scala/reflect/macros/Typers.scala
@@ -27,7 +27,7 @@ trait Typers {
 
   /** Represents mode of operations of the typechecker underlying `c.typecheck` calls.
    *  Is necessary since the shape of the typechecked tree alone is not enough to guess how it should be typechecked.
-   *  Can be EXPRmode (typecheck as a term) or TYPEmode (typecheck as a type).
+   *  Can be EXPRmode (typecheck as a term), TYPEmode (typecheck as a type) or PATTERNmode (typecheck as a pattern).
    */
   // I'd very much like to make use of https://github.com/dsl-paradise/dsl-paradise here!
   type TypecheckMode
@@ -41,6 +41,10 @@ trait Typers {
    */
   val TYPEmode: TypecheckMode
 
+  /** Indicates that an argument to `c.typecheck` should be typechecked as a pattern.
+   */
+  val PATTERNmode: TypecheckMode
+
   /** @see `scala.reflect.macros.TypecheckException`
    */
   type TypecheckException = scala.reflect.macros.TypecheckException
diff --git a/src/reflect/scala/reflect/macros/Universe.scala b/src/reflect/scala/reflect/macros/Universe.scala
index 23cd23cdb0..2dfb4ee0e2 100644
--- a/src/reflect/scala/reflect/macros/Universe.scala
+++ b/src/reflect/scala/reflect/macros/Universe.scala
@@ -138,7 +138,7 @@ abstract class Universe extends scala.reflect.api.Universe {
     /** Retrieves the untyped list of subpatterns attached to selector dummy of an UnApply node.
      *  Useful in writing quasiquoting macros that do pattern matching.
      */
-    def subpatterns(tree: Tree): List[Tree]
+    def subpatterns(tree: Tree): Option[List[Tree]]
   }
 
   /** @group Internal */
diff --git a/test/files/run/macro-enclosures/Impls_Macros_1.scala b/test/files/run/macro-enclosures/Impls_Macros_1.scala
index a0f66a6b98..564cdfa68f 100644
--- a/test/files/run/macro-enclosures/Impls_Macros_1.scala
+++ b/test/files/run/macro-enclosures/Impls_Macros_1.scala
@@ -14,8 +14,8 @@ object Macros {
       println("enclosingTemplate = " + ${c.enclosingTemplate.toString})
       println("enclosingMethod = " + ${c.enclosingMethod.toString})
       println("enclosingDef = " + ${c.enclosingDef.toString})
-      println("enclosingOwner = " + ${c.enclosingOwner.toString})
-      println("enclosingOwnerChain = " + ${chain(c.enclosingOwner).toString})
+      println("enclosingOwner = " + ${c.internal.enclosingOwner.toString})
+      println("enclosingOwnerChain = " + ${chain(c.internal.enclosingOwner).toString})
     """
   }
 
diff --git a/test/files/run/macro-subpatterns.check b/test/files/run/macro-subpatterns.check
index b34d4bf4a1..4997146cf2 100644
--- a/test/files/run/macro-subpatterns.check
+++ b/test/files/run/macro-subpatterns.check
@@ -1,3 +1,3 @@
-List((a @ Extractor((b @ Extractor((c @ _))))))
-List((b @ Extractor((c @ _))))
-List((c @ _))
+Some(List((a @ Extractor((b @ Extractor((c @ _)))))))
+Some(List((b @ Extractor((c @ _)))))
+Some(List((c @ _)))