Merge pull request #3865 from xeno-by/topic/extractor-macros-210x

[backport] transformers no longer ignore UnApply.fun

3 files changed, 50 insertions, 0 deletions

diff --git a/test/files/run/t7871.check b/test/files/run/t7871.check
new file mode 100644
index 0000000000..ce6efd812d
--- /dev/null
+++ b/test/files/run/t7871.check
@@ -0,0 +1 @@
+(SomeTree,SomeTree)
diff --git a/test/files/run/t7871/Macros_1.scala b/test/files/run/t7871/Macros_1.scala
new file mode 100644
index 0000000000..2943445ff8
--- /dev/null
+++ b/test/files/run/t7871/Macros_1.scala
@@ -0,0 +1,43 @@
+import scala.reflect.macros.Context
+import scala.language.experimental.macros
+
+trait Tree
+case object SomeTree extends Tree
+
+object NewQuasiquotes {
+  implicit class QuasiquoteInterpolation(c: StringContext) {
+    object nq {
+      def unapply(t: Tree): Any = macro QuasiquoteMacros.unapplyImpl
+    }
+  }
+}
+
+object QuasiquoteMacros {
+  def unapplyImpl(c: Context)(t: c.Expr[Tree]) = {
+    import c.universe._
+    import Flag._
+    // q"""
+    //   new {
+    //     def unapply(t: Tree) = t match {
+    //       case SomeTree => Some((SomeTree, SomeTree))
+    //       case _ => None
+    //     }
+    //   }.unapply($t)
+    // """
+    c.Expr[Any](Apply(
+      Select(
+        Block(List(
+          ClassDef(Modifiers(FINAL), newTypeName("$anon"), List(),
+            Template(List(Select(Ident(newTermName("scala")), newTypeName("AnyRef"))), emptyValDef, List(
+              DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(),
+                Block(List(Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List())), Literal(Constant(())))),
+              DefDef(Modifiers(), newTermName("unapply"), List(), List(List(ValDef(Modifiers(PARAM), newTermName("t"), Ident(newTypeName("Tree")), EmptyTree))), TypeTree(),
+                Match(
+                  Ident(newTermName("t")), List(
+                    CaseDef(Ident(newTermName("SomeTree")), EmptyTree, Apply(Ident(newTermName("Some")), List(Apply(Select(Ident(newTermName("scala")), newTermName("Tuple2")), List(Ident(newTermName("SomeTree")), Ident(newTermName("SomeTree"))))))),
+                    CaseDef(Ident(nme.WILDCARD), EmptyTree, Ident(newTermName("None")))))))))),
+          Apply(Select(New(Ident(newTypeName("$anon"))), nme.CONSTRUCTOR), List())),
+      newTermName("unapply")),
+    List(t.tree)))
+  }
+}
diff --git a/test/files/run/t7871/Test_2.scala b/test/files/run/t7871/Test_2.scala
new file mode 100644
index 0000000000..3a0b68b568
--- /dev/null
+++ b/test/files/run/t7871/Test_2.scala
@@ -0,0 +1,6 @@
+object Test extends App {
+  import NewQuasiquotes._
+  SomeTree match {
+    case nq"$x + $y" => println((x, y))
+  }
+}