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117 lines
4.1 KiB
C

#if defined(__clang__) && !defined(__OBJC_RUNTIME_INTERNAL__)
#pragma clang system_header
#endif
#include "objc-visibility.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* This file includes all of the hooks that can be used to alter the behaviour
* of the runtime.
*/
#ifndef OBJC_HOOK
#define OBJC_HOOK OBJC_PUBLIC 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.
*/
OBJC_HOOK id (*objc_proxy_lookup)(id receiver, SEL op);
/**
* New runtime forwarding hook. This is no longer used, but is retained to
* prevent errors at link time.
*/
OBJC_HOOK struct objc_slot *(*__objc_msg_forward3)(id, SEL) OBJC_DEPRECATED;
/**
* 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.
*/
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.
*/
OBJC_HOOK IMP (*_objc_selector_type_mismatch2)(Class cls,
SEL selector, struct objc_slot2 *result);
/**
* Legacy hook for when selector types do not match. This is only called
* `_objc_selector_type_mismatch2` is not installed.
*/
OBJC_HOOK struct objc_slot *(*_objc_selector_type_mismatch)(Class cls,
SEL selector, struct objc_slot *result) OBJC_DEPRECATED;
/**
* Returns the object if it is not currently in the process of being
* deallocated. Returns nil otherwise
*
* This hook must be set for weak references to work with automatic reference
* counting for classes that don't provide ARC-compliant retain and release
* methods..
*/
OBJC_HOOK id (*_objc_weak_load)(id object);
/**
* Type for a tracing hook. These are registered to be called before and after
* each message send. The parameters are the receiver and selector for the
* message, the method to be called, a flag indicating the direction, and the
* return value. The flag is 0 when the message is being sent and 1 when it
* returns, the return value is only defined for word-sized scalar returns.
*
* If the hook returns (IMP)0, when invoked in the sending direction, then it
* will not be invoked on return. This is significantly faster.
*
* If the hook returns (IMP)1, when invoked in the sending direction, then it
* will be invoked again on return. The return value is ignored on the second
* call.
*
* If it returns any other value, then the result will be called instead of the
* correct IMP. This allows all messages with a given selector to be
* interposed.
*/
typedef IMP (*objc_tracing_hook)(id, SEL, IMP, int, void*);
/**
* Registers a tracing hook for a specified selector.
*/
OBJC_PUBLIC int objc_registerTracingHook(SEL, objc_tracing_hook);
#ifdef __cplusplus
}
#endif