Merge pull request #4076 from retronym/ticket/8934

SI-8934 Fix whitebox extractor macros in the pres. compiler

8 files changed, 74 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
index 79f5e3bee8..7fcfdf4868 100644
--- a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
+++ b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
@@ -73,9 +73,7 @@ trait ScalacPatternExpanders {
      *  Unfortunately the MethodType does not carry the information of whether
      *  it was unapplySeq, so we have to funnel that information in separately.
      */
-    def unapplyMethodTypes(method: Type, isSeq: Boolean): Extractor = {
-      val whole    = firstParamType(method)
-      val result   = method.finalResultType
+    def unapplyMethodTypes(whole: Type, result: Type, isSeq: Boolean): Extractor = {
       val expanded = (
         if (result =:= BooleanTpe) Nil
         else typeOfMemberNamedGet(result) match {
@@ -126,9 +124,10 @@ trait ScalacPatternExpanders {
       val patterns  = newPatterns(args)
       val isSeq = sel.symbol.name == nme.unapplySeq
       val isUnapply = sel.symbol.name == nme.unapply
+
       val extractor = sel.symbol.name match {
-        case nme.unapply    => unapplyMethodTypes(fn.tpe, isSeq = false)
-        case nme.unapplySeq => unapplyMethodTypes(fn.tpe, isSeq = true)
+        case nme.unapply    => unapplyMethodTypes(firstParamType(fn.tpe), sel.tpe, isSeq = false)
+        case nme.unapplySeq => unapplyMethodTypes(firstParamType(fn.tpe), sel.tpe, isSeq = true)
         case _              => applyMethodTypes(fn.tpe)
       }
 
diff --git a/test/files/pos/t8934a/A_1.scala b/test/files/pos/t8934a/A_1.scala
new file mode 100644
index 0000000000..6c1f29d030
--- /dev/null
+++ b/test/files/pos/t8934a/A_1.scala
@@ -0,0 +1,18 @@
+import language.experimental.macros
+import reflect.macros.whitebox.Context
+
+object Unapply {
+  def impl1(c: Context)(a: c.Tree): c.Tree = {
+    import c.universe._
+    q"(new { def unapply[T](a: String): Option[(Int, String)] = ??? }).unapply($a)"
+  }
+  def unapply(a: Any): Any = macro impl1
+}
+
+object UnapplySeq {
+  def impl1(c: Context)(a: c.Tree): c.Tree = {
+    import c.universe._
+    q"(new { def unapplySeq[T](a: String): Option[(Int, Seq[String])] = ??? }).unapplySeq($a)"
+  }
+  def unapplySeq(a: Any): Any = macro impl1
+}
diff --git a/test/files/pos/t8934a/Test_2.flags b/test/files/pos/t8934a/Test_2.flags
new file mode 100644
index 0000000000..618dfe2b75
--- /dev/null
+++ b/test/files/pos/t8934a/Test_2.flags
@@ -0,0 +1 @@
+-Ystop-after:typer -Ymacro-expand:discard -nowarn
diff --git a/test/files/pos/t8934a/Test_2.scala b/test/files/pos/t8934a/Test_2.scala
new file mode 100644
index 0000000000..e1792ed3c5
--- /dev/null
+++ b/test/files/pos/t8934a/Test_2.scala
@@ -0,0 +1,12 @@
+object Test {
+  "" match {
+    case Unapply(a, b) =>
+      a: Int
+      b: String
+    case UnapplySeq(a, b1, b2) =>
+      a: Int
+      b1: String
+      b2: String
+  }
+}
+// These used to fail `too many patterns` under -Ymacro-expand:discard
diff --git a/test/files/presentation/quasiquotes.flags b/test/files/presentation/quasiquotes.flags
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/files/presentation/quasiquotes.flags
diff --git a/test/files/presentation/t8934.check b/test/files/presentation/t8934.check
new file mode 100644
index 0000000000..0ece87f808
--- /dev/null
+++ b/test/files/presentation/t8934.check
@@ -0,0 +1,2 @@
+reload: Source.scala
+Test OK
diff --git a/test/files/presentation/t8934/Runner.scala b/test/files/presentation/t8934/Runner.scala
new file mode 100644
index 0000000000..944f458391
--- /dev/null
+++ b/test/files/presentation/t8934/Runner.scala
@@ -0,0 +1,27 @@
+import scala.tools.nsc.interactive.tests.InteractiveTest
+import scala.reflect.internal.util.SourceFile
+import scala.tools.nsc.interactive.Response
+
+object Test extends InteractiveTest {
+
+  override def execute(): Unit = {
+    val src = loadSourceAndWaitUntilTypechecked("Source.scala")
+    checkErrors(src)
+  }
+
+  private def loadSourceAndWaitUntilTypechecked(sourceName: String): SourceFile = {
+    val sourceFile = sourceFiles.find(_.file.name == sourceName).head
+    askReload(List(sourceFile)).get
+    askLoadedTyped(sourceFile).get
+    sourceFile
+  }
+
+  private def checkErrors(source: SourceFile): Unit = compiler.getUnitOf(source) match {
+    case Some(unit) =>
+      val problems = unit.problems.toList
+      if(problems.isEmpty) reporter.println("Test OK")
+      else problems.foreach(problem => reporter.println(problem.msg))
+
+    case None => reporter.println("No compilation unit found for " + source.file.name)
+  }
+}
diff --git a/test/files/presentation/t8934/src/Source.scala b/test/files/presentation/t8934/src/Source.scala
new file mode 100644
index 0000000000..769c8fd38b
--- /dev/null
+++ b/test/files/presentation/t8934/src/Source.scala
@@ -0,0 +1,10 @@
+class Quasi {
+  import reflect.runtime.universe._
+
+  def test: Unit = {
+    (null: Any) match {
+      case q"$foo($bar)" =>
+    }
+    ()
+  }
+}