Java Code Examples for jdk.internal.dynalink.CallSiteDescriptor#getNameToken()

@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 findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operator) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    final boolean isScope = NashornCallSiteDescriptor.isScope(desc);

    if (lexicalScope != null && isScope && !NashornCallSiteDescriptor.isApplyToCall(desc)) {
        if (lexicalScope.hasOwnProperty(name)) {
            return lexicalScope.findGetMethod(desc, request, operator);
        }
    }

    final GuardedInvocation invocation =  super.findGetMethod(desc, request, operator);

    // We want to avoid adding our generic lexical scope switchpoint to global constant invocations,
    // because those are invalidated per-key in the addBoundProperties method above.
    // We therefore check if the invocation does already have a switchpoint and the property is non-inherited,
    // assuming this only applies to global constants. If other non-inherited properties will
    // start using switchpoints some time in the future we'll have to revisit this.
    if (isScope && context.getEnv()._es6 && (invocation.getSwitchPoints() == null || !hasOwnProperty(name))) {
        return invocation.addSwitchPoint(getLexicalScopeSwitchPoint());
    }

    return invocation;
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices)
        throws Exception {
    final LinkRequest ncrequest = request.withoutRuntimeContext();
    // BeansLinker already checked that the name is at least 2 elements long and the first element is "dyn".
    final CallSiteDescriptor callSiteDescriptor = ncrequest.getCallSiteDescriptor();
    final String op = callSiteDescriptor.getNameToken(CallSiteDescriptor.OPERATOR);
    // Either dyn:callMethod:name(this[,args]) or dyn:callMethod(this,name[,args]).
    if("callMethod" == op) {
        return getCallPropWithThis(callSiteDescriptor, linkerServices);
    }
    List<String> operations = CallSiteDescriptorFactory.tokenizeOperators(callSiteDescriptor);
    while(!operations.isEmpty()) {
        final GuardedInvocationComponent gic = getGuardedInvocationComponent(callSiteDescriptor, linkerServices,
                operations);
        if(gic != null) {
            return gic.getGuardedInvocation();
        }
        operations = pop(operations);
    }
    return null;
}
 

@Override
public GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final boolean isScope = NashornCallSiteDescriptor.isScope(desc);

    if (lexicalScope != null && isScope) {
        final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
        if (lexicalScope.hasOwnProperty(name)) {
            return lexicalScope.findSetMethod(desc, request);
        }
    }

    final GuardedInvocation invocation = super.findSetMethod(desc, request);

    if (isScope && context.getEnv()._es6) {
        return invocation.addSwitchPoint(getLexicalScopeSwitchPoint());
    }

    return invocation;
}
 

@Override
public GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final boolean isScope = NashornCallSiteDescriptor.isScope(desc);

    if (lexicalScope != null && isScope) {
        final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
        if (lexicalScope.hasOwnProperty(name)) {
            return lexicalScope.findSetMethod(desc, request);
        }
    }

    final GuardedInvocation invocation = super.findSetMethod(desc, request);

    if (isScope && context.getEnv()._es6) {
        return invocation.addSwitchPoint(getLexicalScopeSwitchPoint());
    }

    return invocation;
}
 

/**
 * Handle creation of new attribute.
 * @param desc the call site descriptor
 * @param request the link request
 * @return Link to be invoked at call site.
 */
@Override
public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
    final String propertyName = desc.getNameToken(2);
    final String fullName     = name.isEmpty() ? propertyName : name + "." + propertyName;

    final Context context = Context.getContextTrusted();

    Class<?> javaClass = null;
    try {
        javaClass = context.findClass(fullName);
    } catch (final NoClassDefFoundError | ClassNotFoundException e) {
        //ignored
    }

    if (javaClass == null) {
        set(propertyName, new NativeJavaPackage(fullName, getProto()), false);
    } else {
        set(propertyName, StaticClass.forClass(javaClass), false);
    }

    return super.lookup(desc, request);
}
 

@Override
protected GuardedInvocation findCallMethodMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    if (overrides && super.hasOwnProperty(desc.getNameToken(2))) {
        try {
            final GuardedInvocation inv = super.findCallMethodMethod(desc, request);
            if (inv != null) {
                return inv;
            }
        } catch (final Exception e) {
            //ignored
        }
    }

    return findHook(desc, __call__);
}
 

@Override
protected GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operator) {
    final String name = desc.getNameToken(2);

    // if str.length(), then let the bean linker handle it
    if ("length".equals(name) && "getMethod".equals(operator)) {
        return null;
    }

    return super.findGetMethod(desc, request, operator);
}
 

@Override
protected GuardedInvocation findCallMethodMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    if (overrides && super.hasOwnProperty(desc.getNameToken(2))) {
        try {
            final GuardedInvocation inv = super.findCallMethodMethod(desc, request);
            if (inv != null) {
                return inv;
            }
        } catch (final Exception e) {
            //ignored
        }
    }

    return findHook(desc, __call__);
}
 

private boolean createAndSetProperty(final CallSiteDescriptor desc) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    final Object value = createProperty(name);
    if(value != null) {
        set(name, value, false);
        return true;
    }
    return false;
}
 

@Override
protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    if (overrides && super.hasOwnProperty(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND))) {
        try {
            final GuardedInvocation inv = super.findSetMethod(desc, request);
            if (inv != null) {
                return inv;
            }
        } catch (final Exception e) {
            //ignored
        }
    }

    return findHook(desc, __put__);
}
 

/**
 * Handle creation of new attribute.
 * @param desc the call site descriptor
 * @param request the link request
 * @return Link to be invoked at call site.
 */
@Override
public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
    final String propertyName = desc.getNameToken(2);
    createProperty(propertyName);
    return super.lookup(desc, request);
}
 

@Override
protected GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operation) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    if (overrides && super.hasOwnProperty(name)) {
        try {
            final GuardedInvocation inv = super.findGetMethod(desc, request, operation);
            if (inv != null) {
                return inv;
            }
        } catch (final Exception e) {
            //ignored
        }
    }

    switch(operation) {
    case "getProp":
    case "getElem":
        return findHook(desc, __get__);
    case "getMethod":
        final FindProperty find = adaptee.findProperty(__call__, true);
        if (find != null) {
            final Object value = find.getObjectValue();
            if (value instanceof ScriptFunction) {
                final ScriptFunction func = (ScriptFunction)value;
                // TODO: It's a shame we need to produce a function bound to this and name, when we'd only need it bound
                // to name. Probably not a big deal, but if we can ever make it leaner, it'd be nice.
                return new GuardedInvocation(MH.dropArguments(MH.constant(Object.class,
                        func.createBound(this, new Object[] { name })), 0, Object.class),
                        testJSAdaptor(adaptee, null, null, null),
                        adaptee.getProtoSwitchPoints(__call__, find.getOwner()), null);
            }
        }
        throw typeError("no.such.function", desc.getNameToken(2), ScriptRuntime.safeToString(this));
    default:
        break;
    }

    throw new AssertionError("should not reach here");
}
 

/**
 * Find the appropriate SET method for an invoke dynamic call.
 *
 * @param desc    the call site descriptor
 * @param request the link request
 *
 * @return GuardedInvocation to be invoked at call site.
 */
protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    if (request.isCallSiteUnstable() || hasWithScope()) {
        return findMegaMorphicSetMethod(desc, name);
    }

    final boolean explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);

    /*
     * If doing property set on a scope object, we should stop proto search on the first
     * non-scope object. Without this, for example, when assigning "toString" on global scope,
     * we'll end up assigning it on it's proto - which is Object.prototype.toString !!
     *
     * toString = function() { print("global toString"); } // don't affect Object.prototype.toString
     */
    FindProperty find = findProperty(name, true, this);

    // If it's not a scope search, then we don't want any inherited properties except those with user defined accessors.
    if (find != null && find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) {
        // We should still check if inherited data property is not writable
        if (isExtensible() && !find.getProperty().isWritable()) {
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", true);
        }
        // Otherwise, forget the found property unless this is a scope callsite and the owner is a scope object as well.
        if (!NashornCallSiteDescriptor.isScope(desc) || !find.getOwner().isScope()) {
            find = null;
        }
    }

    if (find != null) {
        if (!find.getProperty().isWritable() && !NashornCallSiteDescriptor.isDeclaration(desc)) {
            if (NashornCallSiteDescriptor.isScope(desc) && find.getProperty().isLexicalBinding()) {
                throw typeError("assign.constant", name); // Overwriting ES6 const should throw also in non-strict mode.
            }
            // Existing, non-writable property
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", true);
        }
    } else {
        if (!isExtensible()) {
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "object.non.extensible", false);
        }
    }

    final GuardedInvocation inv = new SetMethodCreator(this, find, desc, request).createGuardedInvocation(findBuiltinSwitchPoint(name));

    final GlobalConstants globalConstants = getGlobalConstants();
    if (globalConstants != null) {
        final GuardedInvocation cinv = globalConstants.findSetMethod(find, this, inv, desc, request);
        if (cinv != null) {
            return cinv;
        }
    }

    return inv;
}
 

@Override
public GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request) {
    if (request.isCallSiteUnstable()) {
        // Fall back to megamorphic invocation which performs a complete lookup each time without further relinking.
        return super.lookup(desc, request);
    }

    // With scopes can never be observed outside of Nashorn code, so all call sites that can address it will of
    // necessity have a Nashorn descriptor - it is safe to cast.
    final NashornCallSiteDescriptor ndesc = (NashornCallSiteDescriptor)desc;
    FindProperty find = null;
    GuardedInvocation link = null;
    ScriptObject self;

    final boolean isNamedOperation;
    final String name;
    if (desc.getNameTokenCount() > 2) {
        isNamedOperation = true;
        name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    } else {
        isNamedOperation = false;
        name = null;
    }

    self = expression;
    if (isNamedOperation) {
         find = self.findProperty(name, true);
    }

    if (find != null) {
        link = self.lookup(desc, request);
        if (link != null) {
            return fixExpressionCallSite(ndesc, link);
        }
    }

    final ScriptObject scope = getProto();
    if (isNamedOperation) {
        find = scope.findProperty(name, true);
    }

    if (find != null) {
        return fixScopeCallSite(scope.lookup(desc, request), name, find.getOwner());
    }

    // the property is not found - now check for
    // __noSuchProperty__ and __noSuchMethod__ in expression
    if (self != null) {
        final String fallBack;

        final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);

        switch (operator) {
        case "callMethod":
            throw new AssertionError(); // Nashorn never emits callMethod
        case "getMethod":
            fallBack = NO_SUCH_METHOD_NAME;
            break;
        case "getProp":
        case "getElem":
            fallBack = NO_SUCH_PROPERTY_NAME;
            break;
        default:
            fallBack = null;
            break;
        }

        if (fallBack != null) {
            find = self.findProperty(fallBack, true);
            if (find != null) {
                switch (operator) {
                case "getMethod":
                    link = self.noSuchMethod(desc, request);
                    break;
                case "getProp":
                case "getElem":
                    link = self.noSuchProperty(desc, request);
                    break;
                default:
                    break;
                }
            }
        }

        if (link != null) {
            return fixExpressionCallSite(ndesc, link);
        }
    }

    // still not found, may be scope can handle with it's own
    // __noSuchProperty__, __noSuchMethod__ etc.
    link = scope.lookup(desc, request);

    if (link != null) {
        return fixScopeCallSite(link, name, null);
    }

    return null;
}
 

/**
 * Find the appropriate SET method for an invoke dynamic call.
 *
 * @param desc    the call site descriptor
 * @param request the link request
 *
 * @return GuardedInvocation to be invoked at call site.
 */
protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    if (request.isCallSiteUnstable() || hasWithScope()) {
        return findMegaMorphicSetMethod(desc, name);
    }

    final boolean explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);

    /*
     * If doing property set on a scope object, we should stop proto search on the first
     * non-scope object. Without this, for example, when assigning "toString" on global scope,
     * we'll end up assigning it on it's proto - which is Object.prototype.toString !!
     *
     * toString = function() { print("global toString"); } // don't affect Object.prototype.toString
     */
    FindProperty find = findProperty(name, true, this);

    // If it's not a scope search, then we don't want any inherited properties except those with user defined accessors.
    if (find != null && find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) {
        // We should still check if inherited data property is not writable
        if (isExtensible() && !find.getProperty().isWritable()) {
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", true);
        }
        // Otherwise, forget the found property unless this is a scope callsite and the owner is a scope object as well.
        if (!NashornCallSiteDescriptor.isScope(desc) || !find.getOwner().isScope()) {
            find = null;
        }
    }

    if (find != null) {
        if (!find.getProperty().isWritable() && !NashornCallSiteDescriptor.isDeclaration(desc)) {
            if (NashornCallSiteDescriptor.isScope(desc) && find.getProperty().isLexicalBinding()) {
                throw typeError("assign.constant", name); // Overwriting ES6 const should throw also in non-strict mode.
            }
            // Existing, non-writable property
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", true);
        }
    } else {
        if (!isExtensible()) {
            return createEmptySetMethod(desc, explicitInstanceOfCheck, "object.non.extensible", false);
        }
    }

    final GuardedInvocation inv = new SetMethodCreator(this, find, desc, request).createGuardedInvocation(findBuiltinSwitchPoint(name));

    final GlobalConstants globalConstants = getGlobalConstants();
    if (globalConstants != null) {
        final GuardedInvocation cinv = globalConstants.findSetMethod(find, this, inv, desc, request);
        if (cinv != null) {
            return cinv;
        }
    }

    return inv;
}
 

@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)));
}
 

private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
    return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
 

private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc) {
    final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
    final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
    return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
 

@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)));
}