Class compilation error - Inconsistent stackmap ----------------------------------------------- Key: JASSIST-262 URL: https://issues.jboss.org/browse/JASSIST-262 Project: Javassist Issue Type: Bug Affects Versions: 3.20.0-GA Environment: org.javassist:javassist:3.20.0-GA java version "1.8.0_74" Java(TM) SE Runtime Environment (build 1.8.0_74-b02) Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode) Linux 3.13.0-37-generic #64-Ubuntu SMP x86_64 GNU/Linux Reporter: Alexey Kuznetsov Assignee: Shigeru Chiba Fix For: 3.21.0-GA {code:java} package com.company; import javassist.ClassPool; import javassist.CtClass; import javassist.CtMethod; public class Main { public static void main(String[] args) { CtClass badClass = ClassPool.getDefault().makeClass("badClass"); String src = String.join(System.getProperty("line.separator"), "public void eval () {", " if (true) {", " double t=0;", " } else {", " double t=0;", " }", " for (int i=0; i < 2; i++) {", " int a=0;", " int b=0;", " int c=0;", " int d=0;", " if (true) {", " int e = 0;", " }", " }", "}"); System.out.println(src); try { badClass.addMethod(CtMethod.make(src, badClass)); Class clazzz = badClass.toClass(); Object obj = clazzz.newInstance(); // <-- falls here } catch (Exception e) { e.printStackTrace(); } } } {code} After running that i get output: {noformat} public void eval () { if (true) { double t=0; } else { double t=0; } for (int i=0; i < 2; i++) { int a=0; int b=0; int c=0; int d=0; if (true) { int e = 0; } } } Exception in thread "main" java.lang.VerifyError: Inconsistent stackmap frames at branch target 41 Exception Details: Location: badClass.eval()V @41: iinc Reason: Type top (current frame, locals[4]) is not assignable to integer (stack map, locals[4]) Current Frame: bci: @35 flags: { } locals: { 'badClass', top, top, top, top, integer, integer, integer, integer, integer } stack: { integer } Stackmap Frame: bci: @41 flags: { } locals: { 'badClass', top, top, top, integer, integer, integer, integer, integer } stack: { } Bytecode: 0x0000000: 0499 0009 0387 48a7 0006 0387 4a03 3605 0x0000010: 1505 05a2 001c 0336 0603 3607 0336 0803 0x0000020: 3609 0499 0006 0336 0a84 0501 a7ff e4b1 0x0000030: Stackmap Table: same_frame(@10) same_frame(@13) full_frame(@16,{Object[#2],Top,Top,Top,Top,Integer},{}) full_frame(@41,{Object[#2],Top,Top,Top,Integer,Integer,Integer,Integer,Integer},{}) full_frame(@47,{Object[#2],Top,Top,Top,Top,Integer},{}) at java.lang.Class.getDeclaredConstructors0(Native Method) at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) at java.lang.Class.getConstructor0(Class.java:3075) at java.lang.Class.newInstance(Class.java:412) at com.company.Main.main(Main.java:31) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140) Process finished with exit code 1 {noformat}