Examples with FieldVisitor org.objectweb.asm.FieldVisitor used on opensource projects

Example 86 with FieldVisitor

use of org.objectweb.asm.FieldVisitor in project BKCommonLib by bergerhealer.

the class EntityAddRemoveHandler_1_17 method generateLevelCallbackHookType.

private static Class<?> generateLevelCallbackHookType(FastField<Object> callbacksField) {
    try {
        Class<?> levelCallbackType = callbacksField.getType();
        String levelCallbackDesc = MPLType.getDescriptor(levelCallbackType);
        String bkcCallbackDesc = MPLType.getDescriptor(LevelCallbackHandler.class);
        ExtendedClassWriter<Object> cw = ExtendedClassWriter.builder(levelCallbackType).setFlags(ClassWriter.COMPUTE_MAXS).setExactName(EntityAddRemoveHandler_1_17.class.getName() + "$Hook").build();
        FieldVisitor fv;
        MethodVisitor mv;
        // Add field with the base instance
        {
            fv = cw.visitField(ACC_PUBLIC | ACC_FINAL, "base", levelCallbackDesc, null, null);
            fv.visitEnd();
        }
        // Add field with the callback instance
        {
            fv = cw.visitField(ACC_PUBLIC | ACC_FINAL, "callback", bkcCallbackDesc, null, null);
            fv.visitEnd();
        }
        // Add constructor initializing the base instance and the callback handler instance
        {
            mv = cw.visitMethod(ACC_PUBLIC, "<init>", "(" + levelCallbackDesc + bkcCallbackDesc + ")V", null, null);
            mv.visitCode();
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
            mv.visitVarInsn(ALOAD, 0);
            mv.visitVarInsn(ALOAD, 1);
            mv.visitFieldInsn(PUTFIELD, cw.getInternalName(), "base", levelCallbackDesc);
            mv.visitVarInsn(ALOAD, 0);
            mv.visitVarInsn(ALOAD, 2);
            mv.visitFieldInsn(PUTFIELD, cw.getInternalName(), "callback", bkcCallbackDesc);
            mv.visitInsn(RETURN);
            mv.visitMaxs(0, 0);
            mv.visitEnd();
        }
        // Override all methods defined by the interface that must be implemented
        for (Method method : levelCallbackType.getMethods()) {
            String name = MPLType.getName(method);
            Class<?>[] params = method.getParameterTypes();
            final String callbackMethodName;
            if (name.equals("b") && params.length == 1 && params[0] == Object.class) {
                callbackMethodName = "onEntityAdded";
            } else if (name.equals("a") && params.length == 1 && params[0] == Object.class) {
                callbackMethodName = "onEntityRemoved";
            } else {
                callbackMethodName = null;
            }
            mv = cw.visitMethod(ACC_PUBLIC, MPLType.getName(method), MPLType.getMethodDescriptor(method), null, null);
            mv.visitCode();
            if (callbackMethodName != null) {
                // Locate the Method instance in the callback class we're going to be calling
                // This shouldn't ever fail.
                Method callbackMethod = Stream.of(LevelCallbackHandler.class.getMethods()).filter(m -> m.getName().equals(callbackMethodName)).findFirst().get();
                // Call the base method, store any return value in a temporary value on the stack
                mv.visitVarInsn(ALOAD, 0);
                mv.visitFieldInsn(GETFIELD, cw.getInternalName(), "base", levelCallbackDesc);
                int reg = MPLType.visitVarILoad(mv, 1, method.getParameterTypes());
                ExtendedClassWriter.visitInvoke(mv, levelCallbackType, method);
                if (method.getReturnType() != void.class) {
                    mv.visitVarInsn(MPLType.getOpcode(method.getReturnType(), ISTORE), reg);
                }
                // Then call our callback hook with the input arguments, discard return value
                mv.visitVarInsn(ALOAD, 0);
                mv.visitFieldInsn(GETFIELD, cw.getInternalName(), "callback", bkcCallbackDesc);
                MPLType.visitVarILoad(mv, 1, method.getParameterTypes());
                ExtendedClassWriter.visitInvoke(mv, LevelCallbackHandler.class, callbackMethod);
                // Finally, return the original return value of the base method (if any)
                if (method.getReturnType() != void.class) {
                    mv.visitVarInsn(MPLType.getOpcode(method.getReturnType(), ILOAD), reg);
                }
            } else {
                // Call base method directly
                mv.visitVarInsn(ALOAD, 0);
                mv.visitFieldInsn(GETFIELD, cw.getInternalName(), "base", levelCallbackDesc);
                MPLType.visitVarILoad(mv, 1, method.getParameterTypes());
                ExtendedClassWriter.visitInvoke(mv, levelCallbackType, method);
            }
            mv.visitInsn(MPLType.getOpcode(method.getReturnType(), IRETURN));
            mv.visitMaxs(0, 0);
            mv.visitEnd();
        }
        // Generate!
        return cw.generate();
    } catch (Throwable t) {
        Logging.LOGGER_REFLECTION.log(Level.SEVERE, "Failed to initialize level hook callback proxy class", t);
        return null;
    }
}

Example 87 with FieldVisitor

use of org.objectweb.asm.FieldVisitor in project BKCommonLib by bergerhealer.

the class NullPacketDataSerializerInit method initialize.

/**
 * Makes sure to initialize the NullPacketDataSerializer.
 * A new class is generated and loaded with a static field storing the instance,
 * with the correct type. Inside generated code, it can be accessed
 * the following way:<br>
 * <br>
 * <pre>com.bergerkiller.bukkit.common.internal.logic.NullPacketDataSerializer.INSTANCE</pre>
 */
public static synchronized void initialize() {
    if (is_initialized) {
        return;
    } else {
        is_initialized = true;
    }
    // Only used on 1.17 and later
    if (CommonBootstrap.evaluateMCVersion("<", "1.17")) {
        return;
    }
    // any of this library's code, so it's fine to keep using that one.
    try {
        Class.forName(CLASS_NAME);
        return;
    } catch (ClassNotFoundException ex) {
    /* expected */
    }
    try {
        Class<?> dataSerializerType = Resolver.loadClass("net.minecraft.network.PacketDataSerializer", false);
        if (dataSerializerType == null) {
            throw new IllegalStateException("PacketDataSerializer class not found in server");
        }
        final ExtendedClassWriter<Object> cw = ExtendedClassWriter.builder(dataSerializerType).setExactName(CLASS_NAME).build();
        // Add a static INSTANCE field
        {
            FieldVisitor fv;
            fv = cw.visitField(ACC_PUBLIC | ACC_STATIC, "INSTANCE", cw.getTypeDescriptor(), null, null);
            fv.visitEnd();
        }
        // Override all non-final non-private member methods of PacketDataSerializer
        ReflectionUtil.getAllMethods(dataSerializerType).filter(m -> {
            int modifiers = m.getModifiers();
            return !Modifier.isStatic(modifiers) && !Modifier.isPrivate(modifiers) && !Modifier.isFinal(modifiers);
        }).forEach(m -> {
            cw.visitMethodReturnConstant(m, BoxedType.getDefaultValue(m.getReturnType()));
        });
        // Instantiate and assign to the INSTANCE field
        Object instance = cw.generateInstanceNull();
        Field f = instance.getClass().getDeclaredField("INSTANCE");
        f.set(null, instance);
    } catch (Throwable t) {
        Logging.LOGGER_REFLECTION.log(Level.SEVERE, "Failed to initialize null packet data serializer", t);
    }
}

Example 88 with FieldVisitor

use of org.objectweb.asm.FieldVisitor in project Payara by payara.

the class CompositeUtil method createField.

/**
 * Add the field to the class, adding the @XmlAttribute annotation for marshalling purposes.
 */
private void createField(ClassWriter cw, String name, Class<?> type) {
    String internalType = getInternalTypeString(type);
    FieldVisitor field = cw.visitField(ACC_PRIVATE, getPropertyName(name), internalType, null, null);
    field.visitAnnotation("Ljavax/xml/bind/annotation/XmlAttribute;", true).visitEnd();
    field.visitEnd();
}

Example 89 with FieldVisitor

use of org.objectweb.asm.FieldVisitor in project baseio by generallycloud.

the class HelloGeneratorClass method generatorHelloClass.

/**
 * 使用构造Hello类class字节码<br/>
 * package中的Hello.java只是代码原型，本例中只供对比用，没有实际使用到这个类。<br/>
 * ASM代码生成工具使用 bytecode
 *
 * @return
 * @throws Exception
 * @author SHANHY
 * @create 2016年2月3日
 */
public static byte[] generatorHelloClass() {
    ClassWriter cw = new ClassWriter(0);
    FieldVisitor fv;
    MethodVisitor mv;
    cw.visit(V1_7, ACC_PUBLIC + ACC_SUPER, "test/others/asm/Hello", null, "java/lang/Object", null);
    cw.visitSource("Hello.java", null);
    {
        fv = cw.visitField(ACC_PUBLIC + ACC_FINAL + ACC_STATIC, "FLAG", "Ljava/lang/String;", null, "\u6211\u662f\u5e38\u91cf");
        fv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        Label l1 = new Label();
        mv.visitLabel(l1);
        mv.visitMaxs(1, 1);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC, "🐳", "()V", null, null);
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitInsn(ICONST_0);
        mv.visitVarInsn(ISTORE, 1);
        Label l1 = new Label();
        mv.visitLabel(l1);
        Label l2 = new Label();
        mv.visitJumpInsn(GOTO, l2);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitFrame(Opcodes.F_APPEND, 1, new Object[] { Opcodes.INTEGER }, 0, null);
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitLdcInsn(">>>>>>>>>>\u6211\u662f\u5e38\u91cf");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        Label l4 = new Label();
        mv.visitLabel(l4);
        mv.visitIincInsn(1, 1);
        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitIntInsn(BIPUSH, 8);
        mv.visitJumpInsn(IF_ICMPLT, l3);
        Label l5 = new Label();
        mv.visitLabel(l5);
        mv.visitInsn(RETURN);
        Label l6 = new Label();
        mv.visitLabel(l6);
        mv.visitMaxs(2, 2);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC, "testList", "()Ljava/util/List;", "()Ljava/util/List<Ljava/lang/String;>;", null);
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitTypeInsn(NEW, "java/util/ArrayList");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", "<init>", "()V", false);
        mv.visitVarInsn(ASTORE, 1);
        Label l1 = new Label();
        mv.visitLabel(l1);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitLdcInsn("Tome");
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
        mv.visitInsn(POP);
        Label l2 = new Label();
        mv.visitLabel(l2);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitLdcInsn("Jack");
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
        mv.visitInsn(POP);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitLdcInsn("Lily");
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
        mv.visitInsn(POP);
        Label l4 = new Label();
        mv.visitLabel(l4);
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP);
        mv.visitLdcInsn(">>>>>>>>>>testList > list.size = ");
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "size", "()I", true);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        Label l5 = new Label();
        mv.visitLabel(l5);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitInsn(ARETURN);
        Label l6 = new Label();
        mv.visitLabel(l6);
        mv.visitMaxs(4, 2);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC + ACC_VARARGS, "testMapList", "(Z[Ljava/util/Map;)Ljava/util/List;", "(Z[Ljava/util/Map<Ljava/lang/String;Ljava/lang/String;>;)Ljava/util/List<Ljava/util/Map<Ljava/lang/String;Ljava/lang/String;>;>;", null);
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitTypeInsn(NEW, "java/util/ArrayList");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", "<init>", "()V", false);
        mv.visitVarInsn(ASTORE, 3);
        Label l1 = new Label();
        mv.visitLabel(l1);
        mv.visitVarInsn(ILOAD, 1);
        Label l2 = new Label();
        mv.visitJumpInsn(IFEQ, l2);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitInsn(DUP);
        mv.visitVarInsn(ASTORE, 7);
        mv.visitInsn(ARRAYLENGTH);
        mv.visitVarInsn(ISTORE, 6);
        mv.visitInsn(ICONST_0);
        mv.visitVarInsn(ISTORE, 5);
        Label l4 = new Label();
        mv.visitJumpInsn(GOTO, l4);
        Label l5 = new Label();
        mv.visitLabel(l5);
        mv.visitFrame(Opcodes.F_FULL, 8, new Object[] { "test/others/asm/Hello", Opcodes.INTEGER, "[Ljava/util/Map;", "java/util/List", Opcodes.TOP, Opcodes.INTEGER, Opcodes.INTEGER, "[Ljava/util/Map;" }, 0, new Object[] {});
        mv.visitVarInsn(ALOAD, 7);
        mv.visitVarInsn(ILOAD, 5);
        mv.visitInsn(AALOAD);
        mv.visitVarInsn(ASTORE, 4);
        Label l6 = new Label();
        mv.visitLabel(l6);
        mv.visitVarInsn(ALOAD, 3);
        mv.visitVarInsn(ALOAD, 4);
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
        mv.visitInsn(POP);
        Label l7 = new Label();
        mv.visitLabel(l7);
        mv.visitIincInsn(5, 1);
        mv.visitLabel(l4);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitVarInsn(ILOAD, 5);
        mv.visitVarInsn(ILOAD, 6);
        mv.visitJumpInsn(IF_ICMPLT, l5);
        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_FULL, 4, new Object[] { "test/others/asm/Hello", Opcodes.INTEGER, "[Ljava/util/Map;", "java/util/List" }, 0, new Object[] {});
        mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP);
        mv.visitLdcInsn(">>>>>>>>>>testMapList > list.size = ");
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ALOAD, 3);
        mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "size", "()I", true);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        Label l8 = new Label();
        mv.visitLabel(l8);
        mv.visitVarInsn(ALOAD, 3);
        mv.visitInsn(ARETURN);
        Label l9 = new Label();
        mv.visitLabel(l9);
        mv.visitMaxs(4, 8);
        mv.visitEnd();
    }
    cw.visitEnd();
    return cw.toByteArray();
}

Example 90 with FieldVisitor

use of org.objectweb.asm.FieldVisitor in project SpongeCommon by SpongePowered.

the class SubtypeFilterDelegate method createFields.

public void createFields(ClassWriter cw) {
    FieldVisitor fv = cw.visitField(0, "classes", "Ljava/util/Set;", "Ljava/util/Set<Ljava/lang/Class<*>;>;", null);
    fv.visitEnd();
}