bool isSubclass(Class cls, Class superclass) {
        if (class_respondsToSelector(object_getClass(cls), 
@selector(isSubclassOfClass:))) {
                return [cls isSubclassOfClass:superclass];
        }
}

> Le 15 déc. 2014 à 16:49, Maxthon Chan <m...@maxchan.info> a écrit :
> 
> But I still need some way to tell them from NSObject/NSProxy decedents from 
> my class walking. Any method calling will cause a crash there.
> 
>> On Dec 15, 2014, at 23:48, Clark S. Cox III <clarkc...@gmail.com> wrote:
>> 
>> That does not mean that they're using "Object" only that they're using a 
>> base class other than "NSObject" or "NSProxy". Why can't you just ignore 
>> such classes?
>> 
>> Sent from my iPhone
>> 
>> On Dec 14, 2014, at 23:31, Maxthon Chan <m...@maxchan.info 
>> <mailto:m...@maxchan.info>> wrote:
>> 
>>> My class scanning returned several OS* classes that does not conform to 
>>> NSObject protocol.
>>> 
>>>> On Dec 15, 2014, at 00:29, Clark S. Cox III <clarkc...@gmail.com 
>>>> <mailto:clarkc...@gmail.com>> wrote:
>>>> 
>>>>> 
>>>>> On Dec 13, 2014, at 11:57, Maxthon Chan <m...@maxchan.info 
>>>>> <mailto:m...@maxchan.info>> wrote:
>>>>> 
>>>>> NSProxy checking actually work, but throwing those classes that derive 
>>>>> from Object class (note I used capitalised O here, the old Object class 
>>>>> from early NeXT times, also used heavily in OS X kernel, GCD and Mach 
>>>>> ports)
>>>> 
>>>> What makes you think that Object is used in *any* of those places?
>>>> 
>>>>> into the mix means that no method can be sent before class is determined. 
>>>>> I would suggest Apple add one runtime function class_isSubclassOfClass() 
>>>>> that mirrors the functionality of NSObject and NSProxy method 
>>>>> isSubclassOfClass so that derivatives of the old Object class can be 
>>>>> detected more easily.
>>>>> 
>>>>>> On Dec 14, 2014, at 03:49, Gary L. Wade <garyw...@desisoftsystems.com 
>>>>>> <mailto:garyw...@desisoftsystems.com>> wrote:
>>>>>> 
>>>>>> Are you saying that Apple's well-documented approach to see if an object 
>>>>>> is derived from NSProxy does not work? If that's the case, you need to 
>>>>>> submit a bug report to Apple. That's a serious issue that only Apple can 
>>>>>> help you with.
>>>>>> 
>>>>>> If you are using objects not derived from NSObject nor NSProxy, then 
>>>>>> change your design.
>>>>>> --
>>>>>> Gary L. Wade (Sent from my iPad)
>>>>>> http://www.garywade.com/ <http://www.garywade.com/>
>>>>>> 
>>>>>>> On Dec 13, 2014, at 11:40 AM, Maxthon Chan <m...@maxchan.info 
>>>>>>> <mailto:m...@maxchan.info>> wrote:
>>>>>>> 
>>>>>>> Ain’t work! Will crash if an Object derivative showed up.
>>>>>>> 
>>>>>>> I am scanning ALL loaded classes and only subclasses of a certain class 
>>>>>>> is interested. But due to the nature of this class scanning before I 
>>>>>>> can make sure that the class derives from NSObject I cannot call any 
>>>>>>> method on it.
>>>>>>> 
>>>>>>>> On Dec 14, 2014, at 03:34, Gary L. Wade <garyw...@desisoftsystems.com 
>>>>>>>> <mailto:garyw...@desisoftsystems.com>> wrote:
>>>>>>>> 
>>>>>>>> If all you care about is if an object is a proxy or not, look at 
>>>>>>>> isProxy.
>>>>>>>> --
>>>>>>>> Gary L. Wade (Sent from my iPad)
>>>>>>>> http://www.garywade.com/ <http://www.garywade.com/>
>>>>>>>> 
>>>>>>>>> On Dec 13, 2014, at 11:06 AM, Maxthon Chan <m...@maxchan.info 
>>>>>>>>> <mailto:m...@maxchan.info>> wrote:
>>>>>>>>> 
>>>>>>>>> What I am doing here is scanning all loaded classes for subclasses of 
>>>>>>>>> a certain class. Before any NSObject method can be issued I have to 
>>>>>>>>> check if it is actually NSObject or NSProxy derivative instead of an 
>>>>>>>>> Object derivative that does not support NSObject methods. This calls 
>>>>>>>>> for runtime equivalent for one of the following NSObject methods:
>>>>>>>>> 
>>>>>>>>> - [NSObject respondsToSelector:(SEL)aSelector] = 
>>>>>>>>> class_respondsToSelector(Class, SEL) // this crashed.
>>>>>>>>> + [NSObject conformsToProtocol:(Protocol *)aProtocol] = 
>>>>>>>>> class_conformsToProtocol(Class, Protocol *) // check for NSObject 
>>>>>>>>> protocol, this does not work.
>>>>>>>>> + [NSObject isSubclassOfClass:(Class)aClass] // no equivalent, have 
>>>>>>>>> to implement it myself
>>>>>>>>> 
>>>>>>>>> I ended up creating this:
>>>>>>>>> 
>>>>>>>>> BOOL class_isSubclassOfClass(Class cls, Class other)
>>>>>>>>> {
>>>>>>>>> for (Class c = cls; c; c = class_getSuperclass(c))
>>>>>>>>>  if (c == other)
>>>>>>>>>      return YES;
>>>>>>>>> return NO;
>>>>>>>>> }
>>>>>>>>> 
>>>>>>>>> If i remembered it right GNUstep runtime have this function. I will 
>>>>>>>>> file a bug report to Apple and ask them to add this, as it is useful 
>>>>>>>>> in class scanning and i am using this technique heavily in jailbreak 
>>>>>>>>> detection.
>>>>>>>>> 
>>>>>>>>>> On Dec 14, 2014, at 01:20, Kyle Sluder <k...@ksluder.com 
>>>>>>>>>> <mailto:k...@ksluder.com>> wrote:
>>>>>>>>>> 
>>>>>>>>>> On Sat, Dec 13, 2014, at 10:19 AM, Phillip Mills wrote:
>>>>>>>>>>> Why do you think the problem is with “respondsToSelector:”?  The 
>>>>>>>>>>> error
>>>>>>>>>>> says you’re accessing past the end of a string.
>>>>>>>>>> 
>>>>>>>>>> Because the crash happens in a call stack that originates in
>>>>>>>>>> class_respondsToSelector, and involves none of Maxthon's code.
>>>>>>>>>> 
>>>>>>>>>> --Kyle Sluder
>>>>>>> 
>>>>> 
>>>>> _______________________________________________
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>>>>> 
>>>>> This email sent to clarkc...@gmail.com <mailto:clarkc...@gmail.com>
> 
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