Java Code Examples for jdk.internal.org.objectweb.asm.MethodVisitor#visitCode()

/**
 * The bytes for D, a NOT abstract class extending abstract class C without
 * supplying an implementation for abstract method m. There is a default
 * method in the interface I, but it should lose to the abstract class.
 *
 * @return
 * @throws Exception
 */
public static byte[] bytesForD() throws Exception {

    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES
            | ClassWriter.COMPUTE_MAXS);
    MethodVisitor mv;

    cw.visit(V1_8, ACC_PUBLIC + ACC_SUPER, "p/D", null, "p/C", null);

    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "p/C", "<init>", "()V");
        mv.visitInsn(RETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

void addConstructor(BinderClassWriter cw) {
    MethodType constrType = MethodType.methodType(void.class, VarForm.class, boolean.class, long.class, long.class, long.class, long[].class);
    MethodVisitor mv = cw.visitMethod(0, "<init>", constrType.toMethodDescriptorString(), null, null);
    mv.visitCode();
    //super call
    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, 1);
    mv.visitTypeInsn(CHECKCAST, Type.getInternalName(VarForm.class));
    mv.visitVarInsn(ILOAD, 2);
    mv.visitVarInsn(LLOAD, 3);
    mv.visitVarInsn(LLOAD, 5);
    mv.visitVarInsn(LLOAD, 7);
    mv.visitMethodInsn(INVOKESPECIAL, Type.getInternalName(BASE_CLASS), "<init>",
            MethodType.methodType(void.class, VarForm.class, boolean.class, long.class, long.class, long.class).toMethodDescriptorString(), false);
    //init dimensions
    for (int i = 0 ; i < dimensions ; i++) {
        mv.visitVarInsn(ALOAD, 0);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitLdcInsn(i);
        mv.visitInsn(LALOAD);
        mv.visitFieldInsn(PUTFIELD, implClassName, "dim" + i, "J");
    }
    mv.visitInsn(RETURN);
    mv.visitMaxs(0, 0);
    mv.visitEnd();
}
 

private void emitStaticInitializer() {
    final String className = scriptClassInfo.getJavaName();
    if (! staticInitFound) {
        // no user written <clinit> and so create one
        final MethodVisitor mv = ClassGenerator.makeStaticInitializer(this);
        mv.visitCode();
        mv.visitInsn(RETURN);
        mv.visitMaxs(Short.MAX_VALUE, 0);
        mv.visitEnd();
    }
    // Now generate $clinit$
    final MethodGenerator mi = ClassGenerator.makeStaticInitializer(this, $CLINIT$);
    ClassGenerator.emitStaticInitPrefix(mi, className, memberCount);
    if (memberCount > 0) {
        for (final MemberInfo memInfo : scriptClassInfo.getMembers()) {
            if (memInfo.isInstanceProperty() || memInfo.isInstanceFunction()) {
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo);
            } else if (memInfo.isInstanceGetter()) {
                final MemberInfo setter = scriptClassInfo.findSetter(memInfo);
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo, setter);
            }
        }
    }
    ClassGenerator.emitStaticInitSuffix(mi, className);
}
 

/**
 * The bytes for D, a NOT abstract class extending abstract class C without
 * supplying an implementation for abstract method m. There is a default
 * method in the interface I, but it should lose to the abstract class.
 *
 * @return
 * @throws Exception
 */
public static byte[] bytesForD() throws Exception {

    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES
            | ClassWriter.COMPUTE_MAXS);
    MethodVisitor mv;

    cw.visit(V1_8, ACC_PUBLIC + ACC_SUPER, "p/D", null, "p/C", null);

    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "p/C", "<init>", "()V");
        mv.visitInsn(RETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

private void emitStaticInitializer() {
    final String className = scriptClassInfo.getJavaName();
    if (! staticInitFound) {
        // no user written <clinit> and so create one
        final MethodVisitor mv = ClassGenerator.makeStaticInitializer(this);
        mv.visitCode();
        mv.visitInsn(RETURN);
        mv.visitMaxs(Short.MAX_VALUE, 0);
        mv.visitEnd();
    }
    // Now generate $clinit$
    final MethodGenerator mi = ClassGenerator.makeStaticInitializer(this, $CLINIT$);
    ClassGenerator.emitStaticInitPrefix(mi, className, memberCount);
    if (memberCount > 0) {
        for (final MemberInfo memInfo : scriptClassInfo.getMembers()) {
            if (memInfo.isInstanceProperty() || memInfo.isInstanceFunction()) {
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo);
            } else if (memInfo.isInstanceGetter()) {
                final MemberInfo setter = scriptClassInfo.findSetter(memInfo);
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo, setter);
            }
        }
    }
    ClassGenerator.emitStaticInitSuffix(mi, className);
}
 

public static void writeClassFile() throws Exception {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;

    cw.visit(99, ACC_PUBLIC + ACC_SUPER, "ClassFile", null, "java/lang/Object", null);
    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();
    cw.visitEnd();

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

private void emitStaticInitializer() {
    final String className = scriptClassInfo.getJavaName();
    if (! staticInitFound) {
        // no user written <clinit> and so create one
        final MethodVisitor mv = ClassGenerator.makeStaticInitializer(this);
        mv.visitCode();
        mv.visitInsn(RETURN);
        mv.visitMaxs(Short.MAX_VALUE, 0);
        mv.visitEnd();
    }
    // Now generate $clinit$
    final MethodGenerator mi = ClassGenerator.makeStaticInitializer(this, $CLINIT$);
    ClassGenerator.emitStaticInitPrefix(mi, className, memberCount);
    if (memberCount > 0) {
        for (final MemberInfo memInfo : scriptClassInfo.getMembers()) {
            if (memInfo.isInstanceProperty() || memInfo.isInstanceFunction()) {
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo);
            } else if (memInfo.isInstanceGetter()) {
                final MemberInfo setter = scriptClassInfo.findSetter(memInfo);
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo, setter);
            }
        }
    }
    ClassGenerator.emitStaticInitSuffix(mi, className);
}
 

public static byte[] dumpT2() {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;

    cw.visit(52, ACC_PUBLIC | ACC_SUPER, "p1/T2", null, "p1/T1", null);
    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "p1/T1", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        mv.visitMaxs(1, 1);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_ABSTRACT, "m", "()I", null, null);
        mv.visitEnd();
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

/**
 * The bytes for D, a NOT abstract class extending abstract class C without
 * supplying an implementation for abstract method m. There is a default
 * method in the interface I, but it should lose to the abstract class.
 *
 * @return
 * @throws Exception
 */
public static byte[] bytesForD() throws Exception {

    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES
            | ClassWriter.COMPUTE_MAXS);
    MethodVisitor mv;

    cw.visit(V1_8, ACC_PUBLIC + ACC_SUPER, "p/D", null, "p/C", null);

    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "p/C", "<init>", "()V");
        mv.visitInsn(RETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

private void emitStaticInitializer() {
    final String className = scriptClassInfo.getJavaName();
    if (! staticInitFound) {
        // no user written <clinit> and so create one
        final MethodVisitor mv = ClassGenerator.makeStaticInitializer(this);
        mv.visitCode();
        mv.visitInsn(RETURN);
        mv.visitMaxs(Short.MAX_VALUE, 0);
        mv.visitEnd();
    }
    // Now generate $clinit$
    final MethodGenerator mi = ClassGenerator.makeStaticInitializer(this, $CLINIT$);
    ClassGenerator.emitStaticInitPrefix(mi, className, memberCount);
    if (memberCount > 0) {
        for (final MemberInfo memInfo : scriptClassInfo.getMembers()) {
            if (memInfo.isInstanceProperty() || memInfo.isInstanceFunction()) {
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo);
            } else if (memInfo.isInstanceGetter()) {
                final MemberInfo setter = scriptClassInfo.findSetter(memInfo);
                ClassGenerator.linkerAddGetterSetter(mi, className, memInfo, setter);
            }
        }
    }
    ClassGenerator.emitStaticInitSuffix(mi, className);
}
 

private static byte[] loadC(boolean redefine) {
    ClassWriter cw = new ClassWriter(0);

    cw.visit(52, ACC_SUPER | ACC_PUBLIC, "C", null, "java/lang/Object", null);
    {
        MethodVisitor mv;

        mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "m", "()V", null, null);
        mv.visitCode();

        // First time we run we will:
        // 1) Cache resolution errors
        // 2) Redefine the class / method
        // 3) Try to read the resolution errors that were cached
        //
        // The redefined method will never run, throw error to be sure
        if (redefine) {
            createThrowRuntimeExceptionCode(mv, "The redefined method was called");
        } else {
            createMethodBody(mv);
        }
        mv.visitMaxs(3, 0);
        mv.visitEnd();
    }
    cw.visitEnd();
    return cw.toByteArray();
}
 

private byte[] loadClassData(String name) throws Exception {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;
    switch (name) {
        case INTERFACE_NAME:
            cw.visit(V1_8, ACC_ABSTRACT | ACC_INTERFACE | ACC_PUBLIC, INTERFACE_NAME, null, "java/lang/Object", null);
            {
                mv = cw.visitMethod(ACC_PRIVATE, "privInstance", "()I", null, null);
                mv.visitCode();
                mv.visitLdcInsn(EXPECTED);
                mv.visitInsn(IRETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();
            }
            break;
        case CLASS_NAME:
            cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME, null, "java/lang/Object", new String[]{INTERFACE_NAME});
            {
                mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
                mv.visitCode();
                mv.visitVarInsn(ALOAD, 0);
                mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
                mv.visitInsn(RETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();
            }
            break;
        default:
            break;
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

public static void dump_Overrider () throws Exception {

        ClassWriter cw = new ClassWriter(0);
        MethodVisitor mv;
        cw.visit(V1_7, ACC_PUBLIC + ACC_SUPER, "Overrider", null, "HasFinal", null);

        {
            mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
            mv.visitCode();
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKESPECIAL, "HasFinal", "<init>", "()V");
            mv.visitInsn(RETURN);
            mv.visitMaxs(1, 1);
            mv.visitEnd();
        }
        {
            mv = cw.visitMethod(ACC_PUBLIC, "m", "(Ljava/lang/String;)V", null, null);
            mv.visitCode();
            mv.visitInsn(RETURN);
            mv.visitMaxs(0, 2);
            mv.visitEnd();
        }
        {
            mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
            mv.visitCode();
            mv.visitInsn(RETURN);
            mv.visitMaxs(0, 1);
            mv.visitEnd();
        }
        cw.visitEnd();

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

private byte[] loadClassData(String name) throws Exception {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;
    switch (name) {
        case INTERFACE_NAME:
            cw.visit(V1_8, ACC_ABSTRACT | ACC_INTERFACE | ACC_PUBLIC, INTERFACE_NAME, null, "java/lang/Object", null);
            {
                mv = cw.visitMethod(ACC_PRIVATE, "privInstance", "()I", null, null);
                mv.visitCode();
                mv.visitLdcInsn(EXPECTED);
                mv.visitInsn(IRETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();
            }
            break;
        case CLASS_NAME:
            cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME, null, "java/lang/Object", new String[]{INTERFACE_NAME});
            {
                mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
                mv.visitCode();
                mv.visitVarInsn(ALOAD, 0);
                mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
                mv.visitInsn(RETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();
            }
            break;
        default:
            break;
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

private static void generateTestMethod(ClassWriter classWriter) {
    MethodVisitor mv = classWriter.visitMethod(ACC_PUBLIC,
            TestOSRWithNonEmptyStack.METHOD_NAME, "()V", null, null);
    Label osrEntryPoint = new Label();

    mv.visitCode();
    // Push 'this' into stack before OSR entry point to bail out compilation
    mv.visitVarInsn(ALOAD, 0);
    // Setup loop counter
    mv.visitInsn(ICONST_0);
    mv.visitVarInsn(ISTORE, 1);
    // Begin loop
    mv.visitLabel(osrEntryPoint);
    // Increment loop counter
    mv.visitVarInsn(ILOAD, 1);
    mv.visitInsn(ICONST_1);
    mv.visitInsn(IADD);
    // Duplicate it for loop condition check
    mv.visitInsn(DUP);
    mv.visitVarInsn(ISTORE, 1);
    // Check loop condition
    mv.visitLdcInsn(TestOSRWithNonEmptyStack.ITERATIONS);
    mv.visitJumpInsn(IF_ICMPLT, osrEntryPoint);
    // Pop 'this'.
    mv.visitInsn(POP);
    mv.visitInsn(RETURN);

    mv.visitMaxs(0, 0);
    mv.visitEnd();
}
 

public static void writeClassFile(int cfv) throws Exception {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;

    cw.visit(cfv, ACC_PUBLIC + ACC_SUPER, "ClassFile", null, "java/lang/Object", null);
    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();
    mv.visitInsn(ICONST_1);
    mv.visitInsn(ICONST_2);
    mv.visitMultiANewArrayInsn("[I", 2);
    mv.visitVarInsn(ASTORE, 1);
    mv.visitInsn(RETURN);
    mv.visitMaxs(2, 2);
    mv.visitEnd();

    cw.visitEnd();

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

/**
 * The bytecodes for a class p/T defining a methods test() and test(11args)
 * that contain an invokeExact of a particular methodHandle, I.m.
 *
 * Test will be passed values that may imperfectly implement I,
 * and thus may in turn throw exceptions.
 *
 * @return
 * @throws Exception
 */
public static byte[] bytesForT() throws Exception {

    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES
            | ClassWriter.COMPUTE_MAXS);
    MethodVisitor mv;

    cw.visit(V1_8, ACC_PUBLIC + ACC_SUPER, "p/T", null, "java/lang/Object", null);
    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
        mv.visitInsn(RETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    // static int test(I)
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "test", "(Lp/I;)I", null, null);
        mv.visitCode();
        mv.visitLdcInsn(new Handle(Opcodes.H_INVOKEINTERFACE, "p/I", "m", "()I"));
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle",
                "invokeExact", "(Lp/I;)I");
        mv.visitInsn(IRETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    // static int test(I,11args)
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "test", "(Lp/I;BCSIJLjava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)I", null, null);
        mv.visitCode();
        mv.visitLdcInsn(new Handle(Opcodes.H_INVOKEINTERFACE, "p/I", "m", "(BCSIJLjava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)I"));
        mv.visitVarInsn(ALOAD, 0);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitVarInsn(ILOAD, 2);
        mv.visitVarInsn(ILOAD, 3);
        mv.visitVarInsn(ILOAD, 4);
        mv.visitVarInsn(LLOAD, 5);
        mv.visitVarInsn(ALOAD, 7);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitVarInsn(ALOAD, 10);
        mv.visitVarInsn(ALOAD, 11);
        mv.visitVarInsn(ALOAD, 12);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle",
                "invokeExact", "(Lp/I;BCSIJLjava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)I");
        mv.visitInsn(IRETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }
    cw.visitEnd();
    return cw.toByteArray();
}
 

public static byte[] dumpT3() {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;

    cw.visit(52, ACC_PUBLIC + ACC_SUPER, "p1/T3", null, "p1/T2", null);

    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "p1/T2", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        mv.visitMaxs(1, 1);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC, "m", "()I", null, null);
        mv.visitCode();
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitLdcInsn("p1/T3.m()");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "print", "(Ljava/lang/String;)V", false);
        mv.visitIntInsn(BIPUSH, 2);
        mv.visitInsn(IRETURN);
        mv.visitMaxs(2, 1);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "test", "()I", null, null);
        mv.visitCode();
        mv.visitTypeInsn(NEW, "p1/T3");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "p1/T3", "<init>", "()V", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "p1/T2", "m", "()I", false);
        mv.visitInsn(IRETURN);
        mv.visitMaxs(3, 2);
        mv.visitEnd();
    }
    cw.visitEnd();

    return cw.toByteArray();
}
 

@Override
public MethodVisitor visitMethod(final int access, final String name,
        final String desc, final String signature,
        final String[] exceptions) {
    /* a code generate looks like
     *  0: aload_0
     *  1: ldc           #125  // int 1
     *  3: ldc2_w        #126  // long 2l
     *  6: ldc           #128  // float 3.0f
     *  8: ldc2_w        #129  // double 4.0d
     * 11: ldc           #132  // String 5
     * 13: aload_0
     * 14: getfield      #135  // Field nativeCallee:Z
     * 17: ifeq          28
     * 20: invokedynamic #181,  0            // InvokeDynamic #1:calleeNative:(Lcompiler/calls/common/InvokeDynamic;IJFDLjava/lang/String;)Z
     * 25: goto          33
     * 28: invokedynamic #183,  0            // InvokeDynamic #1:callee:(Lcompiler/calls/common/InvokeDynamic;IJFDLjava/lang/String;)Z
     * 33: ldc           #185                // String Call insuccessfull
     * 35: invokestatic  #191                // Method jdk/test/lib/Asserts.assertTrue:(ZLjava/lang/String;)V
     * 38: return
     *
     * or, using java-like pseudo-code
     * if (this.nativeCallee == false) {
     *     invokedynamic-call-return-value = invokedynamic-of-callee
     * } else {
     *     invokedynamic-call-return-value = invokedynamic-of-nativeCallee
     * }
     * Asserts.assertTrue(invokedynamic-call-return-value, error-message);
     * return;
     */
    if (name.equals(CALLER_METHOD_NAME)) {
        MethodVisitor mv = cv.visitMethod(access, name, desc,
                signature, exceptions);
        Label nonNativeLabel = new Label();
        Label checkLabel = new Label();
        MethodType mtype = MethodType.methodType(CallSite.class,
                MethodHandles.Lookup.class, String.class, MethodType.class);
        Handle bootstrap = new Handle(Opcodes.H_INVOKESTATIC, CLASS,
                BOOTSTRAP_METHOD_NAME, mtype.toMethodDescriptorString());
        mv.visitCode();
        // push callee parameters onto stack
        mv.visitVarInsn(Opcodes.ALOAD, 0);//push "this"
        mv.visitLdcInsn(1);
        mv.visitLdcInsn(2L);
        mv.visitLdcInsn(3.0f);
        mv.visitLdcInsn(4.0d);
        mv.visitLdcInsn("5");
        // params loaded. let's decide what method to call
        mv.visitVarInsn(Opcodes.ALOAD, 0); // push "this"
        // get nativeCallee field
        mv.visitFieldInsn(Opcodes.GETFIELD, CLASS, CALL_NATIVE_FIELD,
                CALL_NATIVE_FIELD_DESC);
        // if nativeCallee == false goto nonNativeLabel
        mv.visitJumpInsn(Opcodes.IFEQ, nonNativeLabel);
        // invokedynamic nativeCalleeMethod using bootstrap method
        mv.visitInvokeDynamicInsn(NATIVE_CALLEE_METHOD_NAME,
                CALLEE_METHOD_DESC, bootstrap);
        // goto checkLabel
        mv.visitJumpInsn(Opcodes.GOTO, checkLabel);
        // label: nonNativeLabel
        mv.visitLabel(nonNativeLabel);
        // invokedynamic calleeMethod using bootstrap method
        mv.visitInvokeDynamicInsn(CALLEE_METHOD_NAME, CALLEE_METHOD_DESC,
                bootstrap);
        mv.visitLabel(checkLabel);
        mv.visitLdcInsn(CallsBase.CALL_ERR_MSG);
        mv.visitMethodInsn(Opcodes.INVOKESTATIC, ASSERTS_CLASS,
                ASSERTTRUE_METHOD_NAME, ASSERTTRUE_METHOD_DESC, false);
        // label: return
        mv.visitInsn(Opcodes.RETURN);
        mv.visitMaxs(0, 0);
        mv.visitEnd();
        return null;
    }
    return super.visitMethod(access, name, desc, signature, exceptions);
}
 

private byte[] loadClassData(String name) throws Exception {
    ClassWriter cw = new ClassWriter(0);
    MethodVisitor mv;
    switch (name) {
       case CLASS_NAME_A:
            cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME_A, null, "java/lang/Object", null);
            {
                mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
                mv.visitCode();
                mv.visitVarInsn(ALOAD, 0);
                mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
                mv.visitInsn(RETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();

                mv = cw.visitMethod(ACC_FINAL | ACC_STATIC, "m", "()I", null, null);
                mv.visitCode();
                mv.visitLdcInsn(FAILED);
                mv.visitInsn(IRETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();
            }
            break;
        case CLASS_NAME_B:
            cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME_B, null, CLASS_NAME_A, null);
            {
                mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
                mv.visitCode();
                mv.visitVarInsn(ALOAD, 0);
                mv.visitMethodInsn(INVOKESPECIAL, CLASS_NAME_A, "<init>", "()V");
                mv.visitInsn(RETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();

                mv = cw.visitMethod(ACC_PUBLIC, "m", "()I", null, null);
                mv.visitCode();
                mv.visitLdcInsn(EXPECTED);
                mv.visitInsn(IRETURN);
                mv.visitMaxs(1, 1);
                mv.visitEnd();

            }
            break;
        default:
            break;
    }
    cw.visitEnd();

    return cw.toByteArray();
}