ObjCCallbackFunction.mm [plain text]
/*
* Copyright (C) 2013, 2016 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#import "JavaScriptCore.h"
#if JSC_OBJC_API_ENABLED
#import "APICallbackFunction.h"
#import "APICast.h"
#import "Error.h"
#import "JSCell.h"
#import "JSCInlines.h"
#import "JSContextInternal.h"
#import "JSWrapperMap.h"
#import "JSValueInternal.h"
#import "ObjCCallbackFunction.h"
#import "ObjcRuntimeExtras.h"
#import "StructureInlines.h"
#import <objc/runtime.h>
#import <wtf/RetainPtr.h>
class CallbackArgument {
WTF_MAKE_FAST_ALLOCATED;
public:
virtual ~CallbackArgument();
virtual void set(NSInvocation *, NSInteger, JSContext *, JSValueRef, JSValueRef*) = 0;
std::unique_ptr<CallbackArgument> m_next;
};
CallbackArgument::~CallbackArgument()
{
}
class CallbackArgumentBoolean : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef*) override
{
bool value = JSValueToBoolean([context JSGlobalContextRef], argument);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
template<typename T>
class CallbackArgumentInteger : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
T value = (T)JSC::toInt32(JSValueToNumber([context JSGlobalContextRef], argument, exception));
[invocation setArgument:&value atIndex:argumentNumber];
}
};
template<typename T>
class CallbackArgumentDouble : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
T value = (T)JSValueToNumber([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentJSValue : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef*) override
{
JSValue *value = [JSValue valueWithJSValueRef:argument inContext:context];
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentId : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef*) override
{
id value = valueToObject(context, argument);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentOfClass : public CallbackArgument {
public:
CallbackArgumentOfClass(Class cls)
: m_class(cls)
{
}
private:
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
JSGlobalContextRef contextRef = [context JSGlobalContextRef];
id object = tryUnwrapObjcObject(contextRef, argument);
if (object && [object isKindOfClass:m_class.get()]) {
[invocation setArgument:&object atIndex:argumentNumber];
return;
}
if (JSValueIsNull(contextRef, argument) || JSValueIsUndefined(contextRef, argument)) {
object = nil;
[invocation setArgument:&object atIndex:argumentNumber];
return;
}
*exception = toRef(JSC::createTypeError(toJS(contextRef), "Argument does not match Objective-C Class"_s));
}
RetainPtr<Class> m_class;
};
class CallbackArgumentNSNumber : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
id value = valueToNumber([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentNSString : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
id value = valueToString([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentNSDate : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
id value = valueToDate([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentNSArray : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
id value = valueToArray([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentNSDictionary : public CallbackArgument {
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef* exception) override
{
id value = valueToDictionary([context JSGlobalContextRef], argument, exception);
[invocation setArgument:&value atIndex:argumentNumber];
}
};
class CallbackArgumentStruct : public CallbackArgument {
public:
CallbackArgumentStruct(NSInvocation *conversionInvocation, const char* encodedType)
: m_conversionInvocation(conversionInvocation)
, m_buffer(encodedType)
{
}
private:
void set(NSInvocation *invocation, NSInteger argumentNumber, JSContext *context, JSValueRef argument, JSValueRef*) override
{
JSValue *value = [JSValue valueWithJSValueRef:argument inContext:context];
[m_conversionInvocation invokeWithTarget:value];
[m_conversionInvocation getReturnValue:m_buffer];
[invocation setArgument:m_buffer atIndex:argumentNumber];
}
RetainPtr<NSInvocation> m_conversionInvocation;
StructBuffer m_buffer;
};
class ArgumentTypeDelegate {
public:
typedef std::unique_ptr<CallbackArgument> ResultType;
template<typename T>
static ResultType typeInteger()
{
return std::make_unique<CallbackArgumentInteger<T>>();
}
template<typename T>
static ResultType typeDouble()
{
return std::make_unique<CallbackArgumentDouble<T>>();
}
static ResultType typeBool()
{
return std::make_unique<CallbackArgumentBoolean>();
}
static ResultType typeVoid()
{
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
static ResultType typeId()
{
return std::make_unique<CallbackArgumentId>();
}
static ResultType typeOfClass(const char* begin, const char* end)
{
StringRange copy(begin, end);
Class cls = objc_getClass(copy);
if (!cls)
return nullptr;
if (cls == [JSValue class])
return std::make_unique<CallbackArgumentJSValue>();
if (cls == [NSString class])
return std::make_unique<CallbackArgumentNSString>();
if (cls == [NSNumber class])
return std::make_unique<CallbackArgumentNSNumber>();
if (cls == [NSDate class])
return std::make_unique<CallbackArgumentNSDate>();
if (cls == [NSArray class])
return std::make_unique<CallbackArgumentNSArray>();
if (cls == [NSDictionary class])
return std::make_unique<CallbackArgumentNSDictionary>();
return std::make_unique<CallbackArgumentOfClass>(cls);
}
static ResultType typeBlock(const char*, const char*)
{
return nullptr;
}
static ResultType typeStruct(const char* begin, const char* end)
{
StringRange copy(begin, end);
if (NSInvocation *invocation = valueToTypeInvocationFor(copy))
return std::make_unique<CallbackArgumentStruct>(invocation, copy);
return nullptr;
}
};
class CallbackResult {
WTF_MAKE_FAST_ALLOCATED;
public:
virtual ~CallbackResult()
{
}
virtual JSValueRef get(NSInvocation *, JSContext *, JSValueRef*) = 0;
};
class CallbackResultVoid : public CallbackResult {
JSValueRef get(NSInvocation *, JSContext *context, JSValueRef*) override
{
return JSValueMakeUndefined([context JSGlobalContextRef]);
}
};
class CallbackResultId : public CallbackResult {
JSValueRef get(NSInvocation *invocation, JSContext *context, JSValueRef*) override
{
id value;
[invocation getReturnValue:&value];
return objectToValue(context, value);
}
};
template<typename T>
class CallbackResultNumeric : public CallbackResult {
JSValueRef get(NSInvocation *invocation, JSContext *context, JSValueRef*) override
{
T value;
[invocation getReturnValue:&value];
return JSValueMakeNumber([context JSGlobalContextRef], value);
}
};
class CallbackResultBoolean : public CallbackResult {
JSValueRef get(NSInvocation *invocation, JSContext *context, JSValueRef*) override
{
bool value;
[invocation getReturnValue:&value];
return JSValueMakeBoolean([context JSGlobalContextRef], value);
}
};
class CallbackResultStruct : public CallbackResult {
public:
CallbackResultStruct(NSInvocation *conversionInvocation, const char* encodedType)
: m_conversionInvocation(conversionInvocation)
, m_buffer(encodedType)
{
}
private:
JSValueRef get(NSInvocation *invocation, JSContext *context, JSValueRef*) override
{
[invocation getReturnValue:m_buffer];
[m_conversionInvocation setArgument:m_buffer atIndex:2];
[m_conversionInvocation setArgument:&context atIndex:3];
[m_conversionInvocation invokeWithTarget:[JSValue class]];
JSValue *value;
[m_conversionInvocation getReturnValue:&value];
return valueInternalValue(value);
}
RetainPtr<NSInvocation> m_conversionInvocation;
StructBuffer m_buffer;
};
class ResultTypeDelegate {
public:
typedef std::unique_ptr<CallbackResult> ResultType;
template<typename T>
static ResultType typeInteger()
{
return std::make_unique<CallbackResultNumeric<T>>();
}
template<typename T>
static ResultType typeDouble()
{
return std::make_unique<CallbackResultNumeric<T>>();
}
static ResultType typeBool()
{
return std::make_unique<CallbackResultBoolean>();
}
static ResultType typeVoid()
{
return std::make_unique<CallbackResultVoid>();
}
static ResultType typeId()
{
return std::make_unique<CallbackResultId>();
}
static ResultType typeOfClass(const char*, const char*)
{
return std::make_unique<CallbackResultId>();
}
static ResultType typeBlock(const char*, const char*)
{
return std::make_unique<CallbackResultId>();
}
static ResultType typeStruct(const char* begin, const char* end)
{
StringRange copy(begin, end);
if (NSInvocation *invocation = typeToValueInvocationFor(copy))
return std::make_unique<CallbackResultStruct>(invocation, copy);
return nullptr;
}
};
enum CallbackType {
CallbackInitMethod,
CallbackInstanceMethod,
CallbackClassMethod,
CallbackBlock
};
namespace JSC {
class ObjCCallbackFunctionImpl {
public:
ObjCCallbackFunctionImpl(NSInvocation *invocation, CallbackType type, Class instanceClass, std::unique_ptr<CallbackArgument> arguments, std::unique_ptr<CallbackResult> result)
: m_type(type)
, m_instanceClass(instanceClass)
, m_invocation(invocation)
, m_arguments(WTFMove(arguments))
, m_result(WTFMove(result))
{
ASSERT((type != CallbackInstanceMethod && type != CallbackInitMethod) || instanceClass);
}
void destroy(Heap& heap)
{
// We need to explicitly release the target since we didn't call
// -retainArguments on m_invocation (and we don't want to do so).
if (m_type == CallbackBlock || m_type == CallbackClassMethod)
heap.releaseSoon(adoptNS([m_invocation.get() target]));
m_instanceClass = nil;
}
JSValueRef call(JSContext *context, JSObjectRef thisObject, size_t argumentCount, const JSValueRef arguments[], JSValueRef* exception);
id wrappedBlock()
{
return m_type == CallbackBlock ? [m_invocation target] : nil;
}
id wrappedConstructor()
{
switch (m_type) {
case CallbackBlock:
return [m_invocation target];
case CallbackInitMethod:
return m_instanceClass.get();
default:
return nil;
}
}
CallbackType type() const { return m_type; }
bool isConstructible()
{
return !!wrappedBlock() || m_type == CallbackInitMethod;
}
String name();
private:
CallbackType m_type;
RetainPtr<Class> m_instanceClass;
RetainPtr<NSInvocation> m_invocation;
std::unique_ptr<CallbackArgument> m_arguments;
std::unique_ptr<CallbackResult> m_result;
};
static JSValueRef objCCallbackFunctionCallAsFunction(JSContextRef callerContext, JSObjectRef function, JSObjectRef thisObject, size_t argumentCount, const JSValueRef arguments[], JSValueRef* exception)
{
// Retake the API lock - we need this for a few reasons:
// (1) We don't want to support the C-API's confusing drops-locks-once policy - should only drop locks if we can do so recursively.
// (2) We're calling some JSC internals that require us to be on the 'inside' - e.g. createTypeError.
// (3) We need to be locked (per context would be fine) against conflicting usage of the ObjCCallbackFunction's NSInvocation.
JSC::JSLockHolder locker(toJS(callerContext));
ObjCCallbackFunction* callback = static_cast<ObjCCallbackFunction*>(toJS(function));
ObjCCallbackFunctionImpl* impl = callback->impl();
JSContext *context = [JSContext contextWithJSGlobalContextRef:toGlobalRef(callback->globalObject()->globalExec())];
if (impl->type() == CallbackInitMethod) {
JSGlobalContextRef contextRef = [context JSGlobalContextRef];
*exception = toRef(JSC::createTypeError(toJS(contextRef), "Cannot call a class constructor without |new|"_s));
return JSValueMakeUndefined(contextRef);
}
CallbackData callbackData;
JSValueRef result;
@autoreleasepool {
[context beginCallbackWithData:&callbackData calleeValue:function thisValue:thisObject argumentCount:argumentCount arguments:arguments];
result = impl->call(context, thisObject, argumentCount, arguments, exception);
if (context.exception)
*exception = valueInternalValue(context.exception);
[context endCallbackWithData:&callbackData];
}
return result;
}
static JSObjectRef objCCallbackFunctionCallAsConstructor(JSContextRef callerContext, JSObjectRef constructor, size_t argumentCount, const JSValueRef arguments[], JSValueRef* exception)
{
JSC::JSLockHolder locker(toJS(callerContext));
ObjCCallbackFunction* callback = static_cast<ObjCCallbackFunction*>(toJS(constructor));
ObjCCallbackFunctionImpl* impl = callback->impl();
JSContext *context = [JSContext contextWithJSGlobalContextRef:toGlobalRef(toJS(callerContext)->lexicalGlobalObject()->globalExec())];
CallbackData callbackData;
JSValueRef result;
@autoreleasepool {
[context beginCallbackWithData:&callbackData calleeValue:constructor thisValue:nullptr argumentCount:argumentCount arguments:arguments];
result = impl->call(context, nullptr, argumentCount, arguments, exception);
if (context.exception)
*exception = valueInternalValue(context.exception);
[context endCallbackWithData:&callbackData];
}
JSGlobalContextRef contextRef = [context JSGlobalContextRef];
if (*exception)
return nullptr;
if (!JSValueIsObject(contextRef, result)) {
*exception = toRef(JSC::createTypeError(toJS(contextRef), "Objective-C blocks called as constructors must return an object."_s));
return nullptr;
}
return const_cast<JSObjectRef>(result);
}
const JSC::ClassInfo ObjCCallbackFunction::s_info = { "CallbackFunction", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(ObjCCallbackFunction) };
ObjCCallbackFunction::ObjCCallbackFunction(JSC::VM& vm, JSC::Structure* structure, JSObjectCallAsFunctionCallback functionCallback, JSObjectCallAsConstructorCallback constructCallback, std::unique_ptr<ObjCCallbackFunctionImpl> impl)
: Base(vm, structure, APICallbackFunction::call<ObjCCallbackFunction>, impl->isConstructible() ? APICallbackFunction::construct<ObjCCallbackFunction> : nullptr)
, m_functionCallback(functionCallback)
, m_constructCallback(constructCallback)
, m_impl(WTFMove(impl))
{
}
ObjCCallbackFunction* ObjCCallbackFunction::create(JSC::VM& vm, JSC::JSGlobalObject* globalObject, const String& name, std::unique_ptr<ObjCCallbackFunctionImpl> impl)
{
Structure* structure = globalObject->objcCallbackFunctionStructure();
ObjCCallbackFunction* function = new (NotNull, allocateCell<ObjCCallbackFunction>(vm.heap)) ObjCCallbackFunction(vm, structure, objCCallbackFunctionCallAsFunction, objCCallbackFunctionCallAsConstructor, WTFMove(impl));
function->finishCreation(vm, name);
return function;
}
void ObjCCallbackFunction::destroy(JSCell* cell)
{
ObjCCallbackFunction& function = *static_cast<ObjCCallbackFunction*>(cell);
function.impl()->destroy(*Heap::heap(cell));
function.~ObjCCallbackFunction();
}
String ObjCCallbackFunctionImpl::name()
{
if (m_type == CallbackInitMethod)
return class_getName(m_instanceClass.get());
// FIXME: Maybe we could support having the selector as the name of the non-init
// functions to make it a bit more user-friendly from the JS side?
return "";
}
JSValueRef ObjCCallbackFunctionImpl::call(JSContext *context, JSObjectRef thisObject, size_t argumentCount, const JSValueRef arguments[], JSValueRef* exception)
{
JSGlobalContextRef contextRef = [context JSGlobalContextRef];
id target;
size_t firstArgument;
switch (m_type) {
case CallbackInitMethod: {
RELEASE_ASSERT(!thisObject);
target = [m_instanceClass alloc];
if (!target || ![target isKindOfClass:m_instanceClass.get()]) {
*exception = toRef(JSC::createTypeError(toJS(contextRef), "self type check failed for Objective-C instance method"_s));
return JSValueMakeUndefined(contextRef);
}
[m_invocation setTarget:target];
firstArgument = 2;
break;
}
case CallbackInstanceMethod: {
target = tryUnwrapObjcObject(contextRef, thisObject);
if (!target || ![target isKindOfClass:m_instanceClass.get()]) {
*exception = toRef(JSC::createTypeError(toJS(contextRef), "self type check failed for Objective-C instance method"_s));
return JSValueMakeUndefined(contextRef);
}
[m_invocation setTarget:target];
firstArgument = 2;
break;
}
case CallbackClassMethod:
firstArgument = 2;
break;
case CallbackBlock:
firstArgument = 1;
}
size_t argumentNumber = 0;
for (CallbackArgument* argument = m_arguments.get(); argument; argument = argument->m_next.get()) {
JSValueRef value = argumentNumber < argumentCount ? arguments[argumentNumber] : JSValueMakeUndefined(contextRef);
argument->set(m_invocation.get(), argumentNumber + firstArgument, context, value, exception);
if (*exception)
return JSValueMakeUndefined(contextRef);
++argumentNumber;
}
[m_invocation invoke];
JSValueRef result = m_result->get(m_invocation.get(), context, exception);
// Balance our call to -alloc with a call to -autorelease. We have to do this after calling -init
// because init family methods are allowed to release the allocated object and return something
// else in its place.
if (m_type == CallbackInitMethod) {
id objcResult = tryUnwrapObjcObject(contextRef, result);
if (objcResult)
[objcResult autorelease];
}
return result;
}
} // namespace JSC
static bool blockSignatureContainsClass()
{
static bool containsClass = ^{
id block = ^(NSString *string){ return string; };
return _Block_has_signature((__bridge void*)block) && strstr(_Block_signature((__bridge void*)block), "NSString");
}();
return containsClass;
}
static inline bool skipNumber(const char*& position)
{
if (!isASCIIDigit(*position))
return false;
while (isASCIIDigit(*++position)) { }
return true;
}
static JSObjectRef objCCallbackFunctionForInvocation(JSContext *context, NSInvocation *invocation, CallbackType type, Class instanceClass, const char* signatureWithObjcClasses)
{
if (!signatureWithObjcClasses)
return nullptr;
const char* position = signatureWithObjcClasses;
auto result = parseObjCType<ResultTypeDelegate>(position);
if (!result || !skipNumber(position))
return nullptr;
switch (type) {
case CallbackInitMethod:
case CallbackInstanceMethod:
case CallbackClassMethod:
// Methods are passed two implicit arguments - (id)self, and the selector.
if ('@' != *position++ || !skipNumber(position) || ':' != *position++ || !skipNumber(position))
return nullptr;
break;
case CallbackBlock:
// Blocks are passed one implicit argument - the block, of type "@?".
if (('@' != *position++) || ('?' != *position++) || !skipNumber(position))
return nullptr;
// Only allow arguments of type 'id' if the block signature contains the NS type information.
if ((!blockSignatureContainsClass() && strchr(position, '@')))
return nullptr;
break;
}
std::unique_ptr<CallbackArgument> arguments;
auto* nextArgument = &arguments;
unsigned argumentCount = 0;
while (*position) {
auto argument = parseObjCType<ArgumentTypeDelegate>(position);
if (!argument || !skipNumber(position))
return nullptr;
*nextArgument = WTFMove(argument);
nextArgument = &(*nextArgument)->m_next;
++argumentCount;
}
JSC::ExecState* exec = toJS([context JSGlobalContextRef]);
JSC::VM& vm = exec->vm();
JSC::JSLockHolder locker(vm);
auto impl = std::make_unique<JSC::ObjCCallbackFunctionImpl>(invocation, type, instanceClass, WTFMove(arguments), WTFMove(result));
const String& name = impl->name();
return toRef(JSC::ObjCCallbackFunction::create(vm, exec->lexicalGlobalObject(), name, WTFMove(impl)));
}
JSObjectRef objCCallbackFunctionForInit(JSContext *context, Class cls, Protocol *protocol, SEL sel, const char* types)
{
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[NSMethodSignature signatureWithObjCTypes:types]];
[invocation setSelector:sel];
return objCCallbackFunctionForInvocation(context, invocation, CallbackInitMethod, cls, _protocol_getMethodTypeEncoding(protocol, sel, YES, YES));
}
JSObjectRef objCCallbackFunctionForMethod(JSContext *context, Class cls, Protocol *protocol, BOOL isInstanceMethod, SEL sel, const char* types)
{
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[NSMethodSignature signatureWithObjCTypes:types]];
[invocation setSelector:sel];
if (!isInstanceMethod) {
[invocation setTarget:cls];
// We need to retain the target Class because m_invocation doesn't retain it by default (and we don't want it to).
// FIXME: What releases it?
CFRetain((__bridge CFTypeRef)cls);
}
return objCCallbackFunctionForInvocation(context, invocation, isInstanceMethod ? CallbackInstanceMethod : CallbackClassMethod, isInstanceMethod ? cls : nil, _protocol_getMethodTypeEncoding(protocol, sel, YES, isInstanceMethod));
}
JSObjectRef objCCallbackFunctionForBlock(JSContext *context, id target)
{
if (!_Block_has_signature((__bridge void*)target))
return nullptr;
const char* signature = _Block_signature((__bridge void*)target);
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[NSMethodSignature signatureWithObjCTypes:signature]];
// We don't want to use -retainArguments because that leaks memory. Arguments
// would be retained indefinitely between invocations of the callback.
// Additionally, we copy the target because we want the block to stick around
// until the ObjCCallbackFunctionImpl is destroyed.
[invocation setTarget:[target copy]];
return objCCallbackFunctionForInvocation(context, invocation, CallbackBlock, nil, signature);
}
id tryUnwrapConstructor(JSC::VM* vm, JSObjectRef object)
{
if (!toJS(object)->inherits<JSC::ObjCCallbackFunction>(*vm))
return nil;
JSC::ObjCCallbackFunctionImpl* impl = static_cast<JSC::ObjCCallbackFunction*>(toJS(object))->impl();
if (!impl->isConstructible())
return nil;
return impl->wrappedConstructor();
}
#endif