VerifyError: Expecting a stackmap frame - Switch case statement Java 7 ---------------------------------------------------------------------- Key: JASSIST-241 URL: https://issues.jboss.org/browse/JASSIST-241 Project: Javassist Issue Type: Bug Affects Versions: 3.19.0-GA Environment: jdk7 Reporter: Patson Luk Assignee: Shigeru Chiba Fix For: 3.20.0-GA This could be a duplicate of issue 215 and 205. Tested it on the master (3.19.0-GA) with java 7. Running the below class {code} import java.util.Random; import javassist.ClassPool; import javassist.CtClass; import javassist.CtMethod; public class TestDriver { public static void main(String[] args) throws Exception { ClassPool pool = ClassPool.getDefault(); CtClass cc = pool.get("TestClass"); CtMethod testMethod = cc.getMethod("test", "(Ljava/lang/Object;)V"); testMethod.insertAfter("System.out.println(\"inserted!\");"); cc.toClass(); //invoke it TestClass.test(new Object()); } } class TestClass { public static void test(Object o) { //part 1 if (o == null) { return; } //part 2 int oper = new Random().nextInt(); switch (oper) { case 1: break; } } } {code} Triggers error message as below: {quote} Exception in thread "main" java.lang.VerifyError: Expecting a stackmap frame at branch target 9 in method TestClass.test(Ljava/lang/Object;)V at offset 1 at TestDriver.main(TestDriver.java:19) {quote} *Please take note that:* # This is observed on Java 7. When the same code is run on Java 6, it is fine # Both the "part 1" - return statement (commented in the code above) and "part 2" - switch/case statement have to be there to trigger the error. If either of those are commented out, then the code runs fine