objective c - objc_setAssociatedObject unavailable in iPhone simulator

Question

In the 3.1 SDk, Apple added support for associated objects.

However, the simulator will not compile code that includes references to objc_setAssociatedObject, objc_getAssociatedObject, et al. (Undeclared errors)

Is there away around this? Can I make the iPhone simulator compile this code? I would hate to have to do all testing on the device.

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Update

Bug Filed: rdar://7477326

Answer 1

I don't think this will be fixed in the 3.x SDKs, so another fix is to just define the functions and call through to the next definition via a dynamic lookup.

Header:

#if TARGET_IPHONE_SIMULATOR
enum {
    OBJC_ASSOCIATION_ASSIGN = 0,
    OBJC_ASSOCIATION_RETAIN_NONATOMIC = 1,
    OBJC_ASSOCIATION_COPY_NONATOMIC = 3,
    OBJC_ASSOCIATION_RETAIN = 01401,
    OBJC_ASSOCIATION_COPY = 01403
};
typedef uintptr_t objc_AssociationPolicy;

void objc_setAssociatedObject(id object, void *key, id value, objc_AssociationPolicy policy);
id objc_getAssociatedObject(id object, void *key);
void objc_removeAssociatedObjects(id object);
#endif

Implementation:

#if TARGET_IPHONE_SIMULATOR
void objc_setAssociatedObject(id object, void *key, id value, objc_AssociationPolicy policy) {
    ((void (*)(id, void *, id, objc_AssociationPolicy))
     dlsym(RTLD_NEXT, "objc_setAssociatedObject")) (object, key, value, policy);
}
id objc_getAssociatedObject(id object, void *key) {
    return ((id (*)(id, void *))
            dlsym(RTLD_NEXT, "objc_getAssociatedObject"))(object, key);
}
void objc_removeAssociatedObjects(id object) {
    ((void (*)(id))
     dlsym(RTLD_NEXT, "objc_removeAssociatedObjects"))(object);
}
#endif