Java Code Examples for org.objectweb.asm.tree.MethodNode#visitFieldInsn()

private MethodNode createMethod() {
    final MethodNode methodNode = new MethodNode(ACC_PUBLIC | ACC_STATIC, methodName, "()V", null, null);
    methodNode.visitCode();

    final Label label0 = new Label();
    methodNode.visitLabel(label0);
    methodNode.visitLineNumber(10, label0);
    methodNode.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
    methodNode.visitLdcInsn(text);
    methodNode.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);

    final Label label1 = new Label();
    methodNode.visitLabel(label1);
    methodNode.visitLineNumber(11, label1);
    methodNode.visitInsn(RETURN);

    methodNode.visitMaxs(2, 0);
    methodNode.visitEnd();
    return methodNode;
}
 

public MethodNode createGetter(GetterDefinition getter) {
    MethodNode method = new MethodNode(Opcodes.ACC_PUBLIC, getter.name,
            "()" + getter.signature, null, null);
    if (getter.member) {
        method.visitVarInsn(Opcodes.ALOAD, 0);
        method.visitFieldInsn(Opcodes.GETFIELD, getter.fieldClass,
                getter.fieldName, getter.actualSig);
    } else {
        method.visitFieldInsn(Opcodes.GETSTATIC, getter.fieldClass,
                getter.fieldName, getter.actualSig);
    }

    if (getter.multiplier != 0) {
        method.visitLdcInsn((int) getter.multiplier);
        method.visitInsn(Opcodes.IMUL);
    }

    method.visitInsn(Type.getType(getter.actualSig).getOpcode(Opcodes.IRETURN));
    method.visitMaxs(1, 1);
    method.visitEnd();
    return method;
}
 

public MethodNode createSetter(GetterDefinition getter) {
    MethodNode method = new MethodNode(Opcodes.ACC_PUBLIC, getter.name.replaceFirst("get", "set"),
            "(" + getter.signature + ")V", null, null);
    method.visitVarInsn(Opcodes.ALOAD, 0);
    method.visitVarInsn(Type.getType(getter.actualSig).getOpcode(Opcodes.ILOAD), 1);

    if (getter.actualSig.equals("I") && getter.multiplier != 0) {
        method.visitLdcInsn((int) modInverse(getter.multiplier));
        method.visitInsn(Opcodes.IMUL);
    }
    if (getter.member) {
        method.visitFieldInsn(Opcodes.PUTFIELD, getter.fieldClass,
                getter.fieldName, getter.actualSig);
    } else {
        method.visitFieldInsn(Opcodes.PUTSTATIC, getter.fieldClass,
                getter.fieldName, getter.actualSig);
    }
    method.visitInsn(Opcodes.RETURN);

    method.visitMaxs(1, 1);
    method.visitEnd();
    return method;
}
 

private MethodNode buildTestConstructor() {
    MethodNode methodVisitor = new MethodNode(Opcodes.ACC_PUBLIC, "<init>", "(Lorg/aion/avm/core/persistence/ConstructorThisInterpreterTest;I)V", null, null);
    methodVisitor.visitCode();
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
    methodVisitor.visitInsn(Opcodes.ICONST_5);
    methodVisitor.visitVarInsn(Opcodes.ILOAD, 2);
    Label label2 = new Label();
    methodVisitor.visitJumpInsn(Opcodes.IF_ICMPNE, label2);
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    Label label3 = new Label();
    methodVisitor.visitJumpInsn(Opcodes.GOTO, label3);
    methodVisitor.visitLabel(label2);
    methodVisitor.visitFrame(Opcodes.F_FULL, 3, new Object[] {"org/aion/avm/core/persistence/ConstructorThisInterpreterTest", "org/aion/avm/core/persistence/ConstructorThisInterpreterTest", Opcodes.INTEGER}, 0, new Object[] {});
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
    methodVisitor.visitLabel(label3);
    methodVisitor.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] {"org/aion/avm/core/persistence/ConstructorThisInterpreterTest"});
    methodVisitor.visitVarInsn(Opcodes.ILOAD, 2);
    methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, "org/aion/avm/core/persistence/ConstructorThisInterpreterTest", "bar", "I");
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    methodVisitor.visitInsn(Opcodes.ICONST_1);
    methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, "org/aion/avm/core/persistence/ConstructorThisInterpreterTest", "bar", "I");
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
    methodVisitor.visitInsn(Opcodes.ICONST_2);
    methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, "org/aion/avm/core/persistence/ConstructorThisInterpreterTest", "bar", "I");
    methodVisitor.visitInsn(Opcodes.RETURN);
    methodVisitor.visitMaxs(2, 3);
    methodVisitor.visitEnd();
    return methodVisitor;
}
 

private MethodNode buildSecondConstructor() {
    MethodNode methodVisitor = new MethodNode(Opcodes.ACC_PUBLIC, "<init>", "(Lorg/aion/avm/core/NonStaticInnerClassTarget$Inner;)V", null, null);
    methodVisitor.visitCode();
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
    methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, "org/aion/avm/core/NonStaticInnerClassTarget$Inner$Deeper", "this$1", "Lorg/aion/avm/core/NonStaticInnerClassTarget$Inner;");
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
    methodVisitor.visitInsn(Opcodes.RETURN);
    methodVisitor.visitMaxs(2, 2);
    methodVisitor.visitEnd();
    return methodVisitor;
}
 

private MethodNode stringPool(String className, String methodName, String fieldName, ArrayList<String> strings) {
    MethodNode method = new MethodNode(ACC_PRIVATE | ACC_STATIC | ACC_SYNTHETIC | ACC_BRIDGE, methodName, "()V",
            null, null);

    method.visitCode();
    int numberOfStrings = strings.size();
    if (numberOfStrings <= 5)
        method.visitInsn(numberOfStrings + 3);
    else if (numberOfStrings <= 127)
        method.visitIntInsn(BIPUSH, strings.size());
    else if (numberOfStrings <= 32767)
        method.visitIntInsn(SIPUSH, strings.size());
    else
        method.visitLdcInsn(strings.size());


    method.visitTypeInsn(ANEWARRAY, "java/lang/String");

    for (int i = 0; i < strings.size(); i++) {
        method.visitInsn(DUP);

        if (i <= 5)
            method.visitInsn(i + 3);
        else if (i <= 127)
            method.visitIntInsn(BIPUSH, i);
        else if (i <= 32767)
            method.visitIntInsn(SIPUSH, i);
        else
            method.visitLdcInsn(i);

        method.visitLdcInsn(strings.get(i));
        method.visitInsn(AASTORE);
    }
    method.visitFieldInsn(PUTSTATIC, className, fieldName, "[Ljava/lang/String;");
    method.visitInsn(RETURN);
    method.visitMaxs(3, 0);
    method.visitEnd();

    return method;
}
 

/**
 * Transforms an existin <clinit> method. Adds bytecode before the return, if
 * exists.
 * @param className
 * @param target 
 */
private void transformClassInit(String className, MethodNode target) {
    Type classType = Type.getObjectType(className);
    if (target.instructions.size() > 0) {
        if (target.instructions.getLast().getOpcode() == Opcodes.RETURN) {
            target.instructions.remove(target.instructions.getLast());
        }
    }
    // ldc
    target.visitLdcInsn(classType);
    // invokevirtual --> classloader on stack
    target.visitMethodInsn(
            Opcodes.INVOKEVIRTUAL,
            JAVA_LANG_CLASS,
            CLASS_GET_CLASSLODER_METHOD,
            CLASS_GET_CLASSLOADER_DESC,
            false
    );
    // putstatic
    target.visitFieldInsn(
            Opcodes.PUTSTATIC,
            AGENT_CLASS,
            AGENT_CLASSLOADER_FIELD,
            AGENT_CLASSLOADER_DESC
    );
    target.visitInsn(Opcodes.RETURN);
    // ldc || classloader instance
    target.maxStack = Math.max(target.maxStack, 1);
    target.maxLocals = Math.max(target.maxLocals, 1);
    target.visitEnd();
}