import java.io.File;
import java.io.FileOutputStream;
import java.util.*;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
import jdk.internal.org.objectweb.asm.*;

// BSMCalledTwice generates a class file named "TestC.class"  that contains bytecodes that represent the following program
//
// public class string {
//   public static void main(java.lang.String[] arg) {
//    for (int i=0; i < 2; i++) {
//        try {
//            String f = "friend";
//
// The "hello " + f in the following statement produces an invokedynamic with a BSM of StringConcatFactory.java/makeConcatWithConstants.
// The ASM bellow erroneously puts 2 static arguments, "hello " and "goodbye" on the stack for the BSM. Causing a exception to
// be thrown when creating the CallSite object
//            System.out.println("hello " + f); <--------------- invokedynamic
//
//        } catch (Error e) { System.out.println("Caught Error:"); System.out.println(e.getMessage()); e.printStackTrace(); }
//    }
//  }
//}

public class BSMCalledTwice implements Opcodes {
    static final String classTestCName = "TestC";

public static void main(String[] args) throws Exception {
    ClassLoader cl = new ClassLoader() {
        public Class<?> loadClass(String name) throws ClassNotFoundException {
            if (findLoadedClass(name) != null) {
                return findLoadedClass(name);
            }

            if (classTestCName.equals(name)) {
                byte[] classFile = null;
                try { classFile = dumpTestC(); } catch (Exception e) { }
                return defineClass(classTestCName, classFile, 0, classFile.length);
            }
            return super.loadClass(name);
         }
     };

    cl.loadClass(classTestCName);
}

public static byte[] dumpTestC () throws Exception {
    ClassWriter cw = new ClassWriter(0);
    FieldVisitor fv;
    MethodVisitor mv;
    AnnotationVisitor av0;

    cw.visit(53, ACC_PUBLIC + ACC_SUPER, classTestCName, null, "java/lang/Object", null);

    cw.visitInnerClass("java/lang/invoke/MethodHandles$Lookup", "java/lang/invoke/MethodHandles", "Lookup", ACC_PUBLIC + ACC_FINAL + ACC_STATIC);

    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        mv.visitMaxs(1, 1);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
        mv.visitCode();
        Label l0 = new Label();
        Label l1 = new Label();
        Label l2 = new Label();
        mv.visitTryCatchBlock(l0, l1, l2, "java/lang/Error");
        mv.visitInsn(ICONST_0);
        mv.visitVarInsn(ISTORE, 1);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitFrame(Opcodes.F_APPEND,1, new Object[] {Opcodes.INTEGER}, 0, null);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitInsn(ICONST_2);
        Label l4 = new Label();
        mv.visitJumpInsn(IF_ICMPGE, l4);
        mv.visitLabel(l0);
        mv.visitLdcInsn("friend");
        mv.visitVarInsn(ASTORE, 2);
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitVarInsn(ALOAD, 2);
        mv.visitInvokeDynamicInsn("makeConcatWithConstants", "(Ljava/lang/String;)Ljava/lang/String;", new Handle(Opcodes.H_INVOKESTATIC, "java/lang/invoke/StringConcatFactory", "makeConcatWithConstants", "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;"), new Object[]{"hello \u0001", "goodbye"});
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        mv.visitLabel(l1);
        Label l5 = new Label();
        mv.visitJumpInsn(GOTO, l5);
        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] {"java/lang/Error"});
        mv.visitVarInsn(ASTORE, 2);
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitLdcInsn("Caught Error:");
          mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Error", "getMessage", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Error", "printStackTrace", "()V", false);
        mv.visitLabel(l5);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitIincInsn(1, 1);
        mv.visitJumpInsn(GOTO, l3);
        mv.visitLabel(l4);
        mv.visitFrame(Opcodes.F_CHOP,1, null, 0, null);
        mv.visitInsn(RETURN);
        mv.visitMaxs(2, 3);
        mv.visitEnd();
    }
    cw.visitEnd();

    try(FileOutputStream fos = new FileOutputStream(new File("TestC.class"))) {
        fos.write(cw.toByteArray());
    }
    return cw.toByteArray();
}
}