$ java -cp classes:asm-9.11.1.jar... demo.BrokenGenerate (25.0.5+8-LTS) DROP_STACK_MAPS: verify() -> 1 problem(s) Expecting a stackmap frame at branch target 8 in demo/Broken::pick(int) @1 DROP_STACK_MAPS: defineClass -> java.lang.VerifyError Expecting a stackmap frame at branch target 8 Exception Details: Location: PASS a branching method built without stack maps fails verification PASS the same code with default options verifies ireturn in a String method: build() succeeded (126 bytes) verify: Bad return type in demo/Wrong::bad() @1 (java/lang/String is not assignable from integer_type) PASS verify() catches a wrongly typed return PASS stack underflow is caught while building underflow: build() threw java.lang.IllegalArgumentException Operand stack underflow at bytecode offset 0 of method u() swapped labels: build() succeeded (173 bytes), verify() -> 0 problem(s) swapped labels: defineClass -> java.lang.ClassFormatError: Illegal exception table range in class file demo/Swapped PASS the JVM rejects the swapped exception-table labels exit=0