SPARK-2549 Functions defined inside of other functions trigger failures

tools/src/main/scala/org/apache/spark/tools/GenerateMIMAIgnore.scala

@@ -99,9 +99,25 @@ object GenerateMIMAIgnore {
     (ignoredClasses.flatMap(c => Seq(c, c.replace("$", "#"))).toSet, ignoredMembers.toSet)
   }
 
+  /** Scala reflection does not let us see inner function even if they are upgraded
+    * to public for some reason. So had to resort to java reflection to get all inner
+    * functions with $$ in there name.
+    */
+  def getInnerFunc(classSymbol: unv.ClassSymbol): Seq[String] = {
+    try {
+      Class.forName(classSymbol.fullName, false, classLoader).getMethods.map(_.getName)
+        .filter(_.contains("$$")).map(classSymbol.fullName + "." + _)
+    } catch {
+      case t: Throwable =>
+        println("Error detecting inner functions for class:" + classSymbol.fullName)
+        Seq.empty[String]
+    }
+  }
+
   private def getAnnotatedOrPackagePrivateMembers(classSymbol: unv.ClassSymbol) = {
     classSymbol.typeSignature.members
-      .filter(x => isPackagePrivate(x) || isDeveloperApi(x) || isExperimental(x)).map(_.fullName)
+      .filter(x => isPackagePrivate(x) || isDeveloperApi(x) || isExperimental(x)).map(_.fullName) ++
+    getInnerFunc(classSymbol)
   }
 
   def main(args: Array[String]) {