67 lines
2.4 KiB
C

/**
* This file includes all of the hooks that can be used to alter the behaviour
* of the runtime.
*/
#ifndef OBJC_HOOK
#define OBJC_HOOK extern
#endif
struct objc_category;
/**
* Class lookup hook. Set this to provide a mechanism for resolving classes
* that have not been registered with the runtime. This can be used for lazy
* library loading, for example. The hook takes a class name as an argument
* and returns the class. A JIT compiler could use this to allow classes to be
* compiled the first time that they are looked up. If the class is already
* registered with the runtime, this will not be called, so it can not be used
* for lazy loading of categories.
*/
OBJC_HOOK Class (*_objc_lookup_class)(const char *name);
/**
* Class load callback.
*/
OBJC_HOOK void (*_objc_load_callback)(Class cls, struct objc_category *category);
/**
* The hook used for fast proxy lookups. This takes an object and a selector
* and returns the instance that the message should be forwarded to.
*/
extern id (*objc_proxy_lookup)(id receiver, SEL op);
/**
* New runtime forwarding hook. This might be removed in future - it's
* actually no more expressive than the forward2 hook and forces Foundation to
* do some stuff that the runtime is better suited to.
*/
extern struct objc_slot *(*__objc_msg_forward3)(id, SEL);
/**
* Forwarding hook. Takes an object and a selector and returns a method that
* handles the forwarding.
*/
OBJC_HOOK IMP (*__objc_msg_forward2)(id, SEL);
/**
* Hook defined for handling unhandled exceptions. If the unwind library
* reaches the end of the stack without finding a handler then this hook is
* called.
*/
OBJC_HOOK void (*_objc_unexpected_exception)(id exception);
/**
* Hook defined to return the class to be used for boxing a foreign exception
* type. The class must implement:
*
* + (id)exceptionWithForeignException: (_Unwind_Exception*)ex;
*
* This will return an instance of the class that encapsulates the exception.
*
* Note: Due to limitations of the current ABI, there is no way for the handler
* to
*/
OBJC_HOOK Class (*_objc_class_for_boxing_foreign_exception)(int64_t exceptionClass);
/**
* Hook called when selector type does not match the method type in the
* receiver. This should return the slot to use instead, although it may throw
* an exception or perform some other action.
*/
extern struct objc_slot* (*_objc_selector_type_mismatch)(Class cls,
SEL selector, struct objc_slot *result);