Java Code Examples for jdk.internal.dynalink.linker.LinkRequest#getReceiver()

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
    final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
    final Object self = requestWithoutContext.getReceiver();
    final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
    checkJSObjectClass();

    if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
        // We only support standard "dyn:*[:*]" operations
        return null;
    }

    final GuardedInvocation inv;
    if (jsObjectClass.isInstance(self)) {
        inv = lookup(desc, request, linkerServices);
    } else {
        throw new AssertionError(); // Should never reach here.
    }

    return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
}
 

@Override
public GuardedInvocation getGuardedInvocation(LinkRequest request, final LinkerServices linkerServices)
        throws Exception {
    final CallSiteDescriptor callSiteDescriptor = request.getCallSiteDescriptor();
    final int l = callSiteDescriptor.getNameTokenCount();
    // All names conforming to the dynalang MOP should have at least two tokens, the first one being "dyn"
    if(l < 2 || "dyn" != callSiteDescriptor.getNameToken(CallSiteDescriptor.SCHEME)) {
        return null;
    }

    final Object receiver = request.getReceiver();
    if(receiver == null) {
        // Can't operate on null
        return null;
    }
    return getLinkerForClass(receiver.getClass()).getGuardedInvocation(request, linkerServices);
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices)
        throws Exception {
    final CallSiteDescriptor callSiteDescriptor = request.getCallSiteDescriptor();
    final int l = callSiteDescriptor.getNameTokenCount();
    // All names conforming to the dynalang MOP should have at least two tokens, the first one being "dyn"
    if(l < 2 || "dyn" != callSiteDescriptor.getNameToken(CallSiteDescriptor.SCHEME)) {
        return null;
    }

    final Object receiver = request.getReceiver();
    if(receiver == null) {
        // Can't operate on null
        return null;
    }
    return getLinkerForClass(receiver.getClass()).getGuardedInvocation(request, linkerServices);
}
 

@Override
public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) {
    final Object receiver = linkRequest.getReceiver();
    if(!(receiver instanceof DynamicMethod)) {
        return null;
    }
    final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
    if(desc.getNameTokenCount() != 2 && desc.getNameToken(CallSiteDescriptor.SCHEME) != "dyn") {
        return null;
    }
    final String operator = desc.getNameToken(CallSiteDescriptor.OPERATOR);
    if(operator == "call") {
        final MethodHandle invocation = ((DynamicMethod)receiver).getInvocation(
                CallSiteDescriptorFactory.dropParameterTypes(desc, 0, 1), linkerServices);
        if(invocation == null) {
            return null;
        }
        return new GuardedInvocation(MethodHandles.dropArguments(invocation, 0,
                desc.getMethodType().parameterType(0)), Guards.getIdentityGuard(receiver));
    }
    return null;
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
    final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
    final Object self = requestWithoutContext.getReceiver();
    final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

    if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
        // We only support standard "dyn:*[:*]" operations
        return null;
    }

    final GuardedInvocation inv;
    if (self instanceof JSObject) {
        inv = lookup(desc);
    } else {
        throw new AssertionError(); // Should never reach here.
    }

    return Bootstrap.asType(inv, linkerServices, desc);
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices)
        throws Exception {
    final CallSiteDescriptor callSiteDescriptor = request.getCallSiteDescriptor();
    final int l = callSiteDescriptor.getNameTokenCount();
    // All names conforming to the dynalang MOP should have at least two tokens, the first one being "dyn"
    if(l < 2 || "dyn" != callSiteDescriptor.getNameToken(CallSiteDescriptor.SCHEME)) {
        return null;
    }

    final Object receiver = request.getReceiver();
    if(receiver == null) {
        // Can't operate on null
        return null;
    }
    return getLinkerForClass(receiver.getClass()).getGuardedInvocation(request, linkerServices);
}
 

@Override
protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final Object self = request.getReceiver();
    final Class<?> returnType = desc.getMethodType().returnType();

    if (returnType == Object.class && (self instanceof String || self instanceof ConsString)) {
        try {
            MethodHandle mh = MH.findStatic(MethodHandles.lookup(), NativeString.class, "get", desc.getMethodType());
            return new GuardedInvocation(mh, NashornGuards.getInstanceOf2Guard(String.class, ConsString.class));
        } catch (final LookupException e) {
            // Shouldn't happen. Fall back to super
        }
    }
    return super.findGetIndexMethod(desc, request);
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {
    final Object self = linkRequest.getReceiver();
    final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
    if (self instanceof ConsString) {
        // In order to treat ConsString like a java.lang.String we need a link request with a string receiver.
        final Object[] arguments = linkRequest.getArguments();
        arguments[0] = "";
        final LinkRequest forgedLinkRequest = linkRequest.replaceArguments(desc, arguments);
        final GuardedInvocation invocation = getGuardedInvocation(beansLinker, forgedLinkRequest, linkerServices);
        // If an invocation is found we add a filter that makes it work for both Strings and ConsStrings.
        return invocation == null ? null : invocation.filterArguments(0, FILTER_CONSSTRING);
    }

    if (self != null && "call".equals(desc.getNameToken(CallSiteDescriptor.OPERATOR))) {
        // Support dyn:call on any object that supports some @FunctionalInterface
        // annotated interface. This way Java method, constructor references or
        // implementations of java.util.function.* interfaces can be called as though
        // those are script functions.
        final String name = getFunctionalInterfaceMethodName(self.getClass());
        if (name != null) {
            final MethodType callType = desc.getMethodType();
            // drop callee (Undefined ScriptFunction) and change the request to be dyn:callMethod:<name>
            final NashornCallSiteDescriptor newDesc = NashornCallSiteDescriptor.get(desc.getLookup(),
                    "dyn:callMethod:" + name, desc.getMethodType().dropParameterTypes(1, 2),
                    NashornCallSiteDescriptor.getFlags(desc));
            final GuardedInvocation gi = getGuardedInvocation(beansLinker,
                    linkRequest.replaceArguments(newDesc, linkRequest.getArguments()),
                    new NashornBeansLinkerServices(linkerServices));

            // drop 'thiz' passed from the script.
            return gi.replaceMethods(
                MH.dropArguments(linkerServices.filterInternalObjects(gi.getInvocation()), 1, callType.parameterType(1)),
                gi.getGuard());
        }
    }
    return getGuardedInvocation(beansLinker, linkRequest, linkerServices);
}
 

@Override
protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final Object self = request.getReceiver();
    final Class<?> returnType = desc.getMethodType().returnType();

    if (returnType == Object.class && (self instanceof String || self instanceof ConsString)) {
        try {
            MethodHandle mh = MH.findStatic(MethodHandles.lookup(), NativeString.class, "get", desc.getMethodType());
            return new GuardedInvocation(mh, NashornGuards.getInstanceOf2Guard(String.class, ConsString.class));
        } catch (final LookupException e) {
            // Shouldn't happen. Fall back to super
        }
    }
    return super.findGetIndexMethod(desc, request);
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)
        throws Exception {
    final Object obj = linkRequest.getReceiver();
    if(obj == null) {
        return null;
    }
    for(final TypeBasedGuardingDynamicLinker linker: classToLinker.get(obj.getClass())) {
        final GuardedInvocation invocation = linker.getGuardedInvocation(linkRequest, linkerServices);
        if(invocation != null) {
            return invocation;
        }
    }
    return null;
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
    final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
    final Object self = requestWithoutContext.getReceiver();
    final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

    if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
        // We only support standard "dyn:*[:*]" operations
        return null;
    }

    return Bootstrap.asTypeSafeReturn(getGuardedInvocation(self,  request, desc), linkerServices, desc);
}
 

@Override
protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final Object self = request.getReceiver();
    final Class<?> returnType = desc.getMethodType().returnType();

    if (returnType == Object.class && JSType.isString(self)) {
        try {
            return new GuardedInvocation(MH.findStatic(MethodHandles.lookup(), NativeString.class, "get", desc.getMethodType()), NashornGuards.getStringGuard());
        } catch (final LookupException e) {
            //empty. Shouldn't happen. Fall back to super
        }
    }
    return super.findGetIndexMethod(desc, request);
}
 

private static void checkLinkRequest(final LinkRequest origRequest) {
    final Global global = Context.getGlobal();
    final ClassFilter cf = global.getClassFilter();
    if (cf != null) {
        throw typeError("no.reflection.with.classfilter");
    }

    final SecurityManager sm = System.getSecurityManager();
    if (sm != null) {
        final LinkRequest requestWithoutContext = origRequest.withoutRuntimeContext(); // Nashorn has no runtime context
        final Object self = requestWithoutContext.getReceiver();
        // allow 'static' access on Class objects representing public classes of non-restricted packages
        if ((self instanceof Class) && Modifier.isPublic(((Class<?>)self).getModifiers())) {
            final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
            if(CallSiteDescriptorFactory.tokenizeOperators(desc).contains("getProp")) {
                if (desc.getNameTokenCount() > CallSiteDescriptor.NAME_OPERAND &&
                    "static".equals(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND))) {
                    if (Context.isAccessibleClass((Class<?>)self) && !isReflectionClass((Class<?>)self)) {

                        // If "getProp:static" passes access checks, allow access.
                        return;
                    }
                }
            }
        }
        checkReflectionPermission(sm);
    }
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
    final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
    final Object self = requestWithoutContext.getReceiver();
    final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

    if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
        // We only support standard "dyn:*[:*]" operations
        return null;
    }

    return Bootstrap.asTypeSafeReturn(getGuardedInvocation(self,  request, desc), linkerServices, desc);
}
 

private static void checkLinkRequest(final LinkRequest origRequest) {
    final Global global = Context.getGlobal();
    final ClassFilter cf = global.getClassFilter();
    if (cf != null) {
        throw typeError("no.reflection.with.classfilter");
    }

    final SecurityManager sm = System.getSecurityManager();
    if (sm != null) {
        final LinkRequest requestWithoutContext = origRequest.withoutRuntimeContext(); // Nashorn has no runtime context
        final Object self = requestWithoutContext.getReceiver();
        // allow 'static' access on Class objects representing public classes of non-restricted packages
        if ((self instanceof Class) && Modifier.isPublic(((Class<?>)self).getModifiers())) {
            final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
            if(CallSiteDescriptorFactory.tokenizeOperators(desc).contains("getProp")) {
                if (desc.getNameTokenCount() > CallSiteDescriptor.NAME_OPERAND &&
                    "static".equals(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND))) {
                    if (Context.isAccessibleClass((Class<?>)self) && !isReflectionClass((Class<?>)self)) {

                        // If "getProp:static" passes access checks, allow access.
                        return;
                    }
                }
            }
        }
        checkReflectionPermission(sm);
    }
}
 

private MethodHandle insertAccessorsGetter(final UserAccessorProperty uap, final LinkRequest request, final MethodHandle mh) {
    MethodHandle superGetter = uap.getAccessorsGetter();
    if (isInherited()) {
        superGetter = ScriptObject.addProtoFilter(superGetter, getProtoChainLength());
    }
    if (request != null && !(request.getReceiver() instanceof ScriptObject)) {
        final MethodHandle wrapFilter = Global.getPrimitiveWrapFilter(request.getReceiver());
        superGetter = MH.filterArguments(superGetter, 0, wrapFilter.asType(wrapFilter.type().changeReturnType(superGetter.type().parameterType(0))));
    }
    superGetter = MH.asType(superGetter, superGetter.type().changeParameterType(0, Object.class));

    return MH.foldArguments(mh, superGetter);
}
 

private static void checkLinkRequest(final LinkRequest origRequest) {
    final Global global = Context.getGlobal();
    final ClassFilter cf = global.getClassFilter();
    if (cf != null) {
        throw typeError("no.reflection.with.classfilter");
    }

    final SecurityManager sm = System.getSecurityManager();
    if (sm != null) {
        final LinkRequest requestWithoutContext = origRequest.withoutRuntimeContext(); // Nashorn has no runtime context
        final Object self = requestWithoutContext.getReceiver();
        // allow 'static' access on Class objects representing public classes of non-restricted packages
        if ((self instanceof Class) && Modifier.isPublic(((Class<?>)self).getModifiers())) {
            final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
            if(CallSiteDescriptorFactory.tokenizeOperators(desc).contains("getProp")) {
                if (desc.getNameTokenCount() > CallSiteDescriptor.NAME_OPERAND &&
                    "static".equals(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND))) {
                    if (Context.isAccessibleClass((Class<?>)self) && !isReflectionClass((Class<?>)self)) {

                        // If "getProp:static" passes access checks, allow access.
                        return;
                    }
                }
            }
        }
        checkReflectionPermission(sm);
    }
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)
        throws Exception {
    final Object objSuperAdapter = linkRequest.getReceiver();
    if(!(objSuperAdapter instanceof JavaSuperAdapter)) {
        return null;
    }

    final CallSiteDescriptor descriptor = linkRequest.getCallSiteDescriptor();
    if(!CallSiteDescriptorFactory.tokenizeOperators(descriptor).contains(GET_METHOD)) {
        // We only handle getMethod
        return null;
    }

    final Object adapter = ((JavaSuperAdapter)objSuperAdapter).getAdapter();

    // Replace argument (javaSuperAdapter, ...) => (adapter, ...) when delegating to BeansLinker
    final Object[] args = linkRequest.getArguments();
    args[0] = adapter;

    // Use R(T0, ...) => R(adapter.class, ...) call site type when delegating to BeansLinker.
    final MethodType type = descriptor.getMethodType();
    final Class<?> adapterClass = adapter.getClass();
    final boolean hasFixedName = descriptor.getNameTokenCount() > 2;
    final String opName = hasFixedName ? (DYN_GET_METHOD_FIXED + descriptor.getNameToken(
            CallSiteDescriptor.NAME_OPERAND)) : DYN_GET_METHOD;

    final CallSiteDescriptor newDescriptor = NashornCallSiteDescriptor.get(descriptor.getLookup(), opName,
            type.changeParameterType(0, adapterClass), 0);

    // Delegate to BeansLinker
    final GuardedInvocation guardedInv = NashornBeansLinker.getGuardedInvocation(
            BeansLinker.getLinkerForClass(adapterClass), linkRequest.replaceArguments(newDescriptor, args),
            linkerServices);

    final MethodHandle guard = IS_ADAPTER_OF_CLASS.bindTo(adapterClass);
    if(guardedInv == null) {
        // Short circuit the lookup here for non-existent methods by linking an empty getter. If we just returned
        // null instead, BeansLinker would find final methods on the JavaSuperAdapter instead: getClass() and
        // wait().
        return new GuardedInvocation(MethodHandles.dropArguments(EMPTY_GETTER, 1,type.parameterList().subList(1,
                type.parameterCount())), guard).asType(descriptor);
    }

    final MethodHandle invocation = guardedInv.getInvocation();
    final MethodType invType = invocation.type();
    // For invocation typed R(T0, ...) create a dynamic method binder of type R(R, T0)
    final MethodHandle typedBinder = BIND_DYNAMIC_METHOD.asType(MethodType.methodType(invType.returnType(),
            invType.returnType(), invType.parameterType(0)));
    // For invocation typed R(T0, T1, ...) create a dynamic method binder of type R(R, T0, T1, ...)
    final MethodHandle droppingBinder = MethodHandles.dropArguments(typedBinder, 2,
            invType.parameterList().subList(1, invType.parameterCount()));
    // Finally, fold the invocation into the binder to produce a method handle that will bind every returned
    // DynamicMethod object from dyn:getMethod calls to the actual receiver
    // R(R(T0, T1, ...), T0, T1, ...)
    final MethodHandle bindingInvocation = MethodHandles.foldArguments(droppingBinder, invocation);

    final MethodHandle typedGetAdapter = asFilterType(GET_ADAPTER, 0, invType, type);
    final MethodHandle adaptedInvocation;
    if(hasFixedName) {
        adaptedInvocation = MethodHandles.filterArguments(bindingInvocation, 0, typedGetAdapter);
    } else {
        // Add a filter that'll prepend "super$" to each name passed to the variable-name "dyn:getMethod".
        final MethodHandle typedAddPrefix = asFilterType(ADD_PREFIX_TO_METHOD_NAME, 1, invType, type);
        adaptedInvocation = MethodHandles.filterArguments(bindingInvocation, 0, typedGetAdapter, typedAddPrefix);
    }

    return guardedInv.replaceMethods(adaptedInvocation, guard).asType(descriptor);
}
 

private static GuardedInvocation linkBean(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {
    final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor();
    final Object self = linkRequest.getReceiver();
    final String operator = desc.getFirstOperator();
    switch (operator) {
    case "new":
        if(BeansLinker.isDynamicConstructor(self)) {
            throw typeError("no.constructor.matches.args", ScriptRuntime.safeToString(self));
        }
        if(BeansLinker.isDynamicMethod(self)) {
            throw typeError("method.not.constructor", ScriptRuntime.safeToString(self));
        }
        throw typeError("not.a.function", desc.getFunctionErrorMessage(self));
    case "call":
        if(BeansLinker.isDynamicConstructor(self)) {
            throw typeError("constructor.requires.new", ScriptRuntime.safeToString(self));
        }
        if(BeansLinker.isDynamicMethod(self)) {
            throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self));
        }
        throw typeError("not.a.function", desc.getFunctionErrorMessage(self));
    case "callMethod":
        throw typeError("no.such.function", getArgument(linkRequest), ScriptRuntime.safeToString(self));
    case "getMethod":
        // evaluate to undefined, later on Undefined will take care of throwing TypeError
        return getInvocation(MH.dropArguments(GET_UNDEFINED.get(TYPE_OBJECT_INDEX), 0, Object.class), self, linkerServices, desc);
    case "getProp":
    case "getElem":
        if(NashornCallSiteDescriptor.isOptimistic(desc)) {
            throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
        }
        if (desc.getOperand() != null) {
            return getInvocation(EMPTY_PROP_GETTER, self, linkerServices, desc);
        }
        return getInvocation(EMPTY_ELEM_GETTER, self, linkerServices, desc);
    case "setProp":
    case "setElem": {
        final boolean strict = NashornCallSiteDescriptor.isStrict(desc);
        if (strict) {
            throw typeError("cant.set.property", getArgument(linkRequest), ScriptRuntime.safeToString(self));
        }
        if (desc.getOperand() != null) {
            return getInvocation(EMPTY_PROP_SETTER, self, linkerServices, desc);
        }
        return getInvocation(EMPTY_ELEM_SETTER, self, linkerServices, desc);
    }
    default:
        break;
    }
    throw new AssertionError("unknown call type " + desc);
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {
    final Object objBoundCallable = linkRequest.getReceiver();
    if(!(objBoundCallable instanceof BoundCallable)) {
        return null;
    }

    final CallSiteDescriptor descriptor = linkRequest.getCallSiteDescriptor();
    if (descriptor.getNameTokenCount() < 2 || !"dyn".equals(descriptor.getNameToken(CallSiteDescriptor.SCHEME))) {
        return null;
    }
    final String operation = descriptor.getNameToken(CallSiteDescriptor.OPERATOR);
    // We need to distinguish "dyn:new" from "dyn:call" because "dyn:call" sites have parameter list of the form
    // "callee, this, args", while "dyn:call" sites have "callee, args" -- they lack the "this" parameter.
    final boolean isCall;
    if ("new".equals(operation)) {
        isCall = false;
    } else if ("call".equals(operation)) {
        isCall = true;
    } else {
        // Only dyn:call and dyn:new are supported.
        return null;
    }
    final BoundCallable boundCallable = (BoundCallable)objBoundCallable;
    final Object callable = boundCallable.getCallable();
    final Object boundThis = boundCallable.getBoundThis();

    // We need to ask the linker services for a delegate invocation on the target callable.

    // Replace arguments (boundCallable[, this], args) => (callable[, boundThis], boundArgs, args) when delegating
    final Object[] args = linkRequest.getArguments();
    final Object[] boundArgs = boundCallable.getBoundArgs();
    final int argsLen = args.length;
    final int boundArgsLen = boundArgs.length;
    final Object[] newArgs = new Object[argsLen + boundArgsLen];
    newArgs[0] = callable;
    final int firstArgIndex;
    if (isCall) {
        newArgs[1] = boundThis;
        firstArgIndex = 2;
    } else {
        firstArgIndex = 1;
    }
    System.arraycopy(boundArgs, 0, newArgs, firstArgIndex, boundArgsLen);
    System.arraycopy(args, firstArgIndex, newArgs, firstArgIndex + boundArgsLen, argsLen - firstArgIndex);

    // Use R(T0, T1, T2, ...) => R(callable.class, boundThis.class, boundArg0.class, ..., boundArgn.class, T2, ...)
    // call site type when delegating to underlying linker (for dyn:new, there's no this).
    final MethodType type = descriptor.getMethodType();
    // Use R(T0, ...) => R(callable.class, ...)
    MethodType newMethodType = descriptor.getMethodType().changeParameterType(0, callable.getClass());
    if (isCall) {
        // R(callable.class, T1, ...) => R(callable.class, boundThis.class, ...)
        newMethodType = newMethodType.changeParameterType(1, boundThis == null? Object.class : boundThis.getClass());
    }
    // R(callable.class[, boundThis.class], T2, ...) => R(callable.class[, boundThis.class], boundArg0.class, ..., boundArgn.class, T2, ...)
    for(int i = boundArgs.length; i-- > 0;) {
        newMethodType = newMethodType.insertParameterTypes(firstArgIndex, boundArgs[i] == null ? Object.class : boundArgs[i].getClass());
    }
    final CallSiteDescriptor newDescriptor = descriptor.changeMethodType(newMethodType);

    // Delegate to target's linker
    final GuardedInvocation inv = linkerServices.getGuardedInvocation(linkRequest.replaceArguments(newDescriptor, newArgs));
    if(inv == null) {
        return null;
    }

    // Bind (callable[, boundThis], boundArgs) to the delegate handle
    final MethodHandle boundHandle = MethodHandles.insertArguments(inv.getInvocation(), 0,
            Arrays.copyOf(newArgs, firstArgIndex + boundArgs.length));
    final Class<?> p0Type = type.parameterType(0);
    final MethodHandle droppingHandle;
    if (isCall) {
        // Ignore incoming boundCallable and this
        droppingHandle = MethodHandles.dropArguments(boundHandle, 0, p0Type, type.parameterType(1));
    } else {
        // Ignore incoming boundCallable
        droppingHandle = MethodHandles.dropArguments(boundHandle, 0, p0Type);
    }
    // Identity guard on boundCallable object
    final MethodHandle newGuard = Guards.getIdentityGuard(boundCallable);
    return inv.replaceMethods(droppingHandle, newGuard.asType(newGuard.type().changeParameterType(0, p0Type)));
}