1 files changed, 32 insertions, 0 deletions
diff --git a/test/files/jvm/bytecode-test-example/Test.scala b/test/files/jvm/bytecode-test-example/Test.scala
new file mode 100644
index 0000000000..d668059cb7
--- /dev/null
+++ b/test/files/jvm/bytecode-test-example/Test.scala
@@ -0,0 +1,32 @@
+import scala.tools.partest.BytecodeTest
+
+import scala.tools.nsc.util.JavaClassPath
+import java.io.InputStream
+import scala.tools.asm
+import asm.ClassReader
+import asm.tree.{ClassNode, InsnList}
+import scala.collection.JavaConverters._
+
+object Test extends BytecodeTest {
+  def show: Unit = {
+    val classNode = loadClassNode("Foo_1")
+    val methodNode = getMethod(classNode, "foo")
+    println(countNullChecks(methodNode.instructions))
+  }
+
+  def countNullChecks(insnList: InsnList): Int = {
+    /** Is given instruction a null check?
+     *  NOTE
+     *   This will detect direct null compparsion as in
+     *    if (x == null) ...
+     *   and not indirect as in
+     *     val foo = null
+     *     if (x == foo) ...
+     */
+    def isNullCheck(node: asm.tree.AbstractInsnNode): Boolean = {
+      val opcode = node.getOpcode
+      (opcode == asm.Opcodes.IFNULL) || (opcode == asm.Opcodes.IFNONNULL)
+    }
+    insnList.iterator.asScala.count(isNullCheck)
+  }
+}