ObjFW  Diff

    objc_enumeration_mutation_handler_t _Nullable handler);
extern id _Nullable objc_constructInstance(Class _Nullable class_,
    void *_Nullable bytes);
extern void *_Nullable objc_destructInstance(id _Nullable object);
extern void *_Null_unspecified objc_autoreleasePoolPush(void);
extern void objc_autoreleasePoolPop(void *_Null_unspecified pool);
extern id _Nullable _objc_rootAutorelease(id _Nullable object);

/*!
 * @brief Sets the tagged pointer secret.
 *
 * @param secret A secret, random value that will be used to XOR all tagged
 *		 pointers with
 */
extern void objc_setTaggedPointerSecret(uintptr_t secret);

/*!
 * @brief Registers a class for tagged pointers.
 *
 * @param class The class to register for tagged pointers
 * @return The tagged pointer ID for the registered class
 */
extern int objc_registerTaggedPointerClass(Class _Nonnull class);

/*!
 * @brief Returns whether the specified object is a tagged pointer.
 *
 * @param object The object to inspect
 * @return Whether the specified object is a tagged pointer
 */
static inline bool
object_isTaggedPointer(id _Nullable object)
{
	uintptr_t pointer = (uintptr_t)object;

	return pointer & 1;
}

extern Class _Nullable object_getTaggedPointerClass(id _Nonnull object);

/*!
 * @brief Returns the value of the specified tagged pointer.
 *
 * @param object The object whose tagged pointer value should be returned
 * @return The tagged pointer value of the object
 */
extern uintptr_t object_getTaggedPointerValue(id _Nonnull object);

/*!
 * @brief Creates a new tagged pointer.
 *
 * @param class The tag ID for the tagged pointer class to use
 * @param value The value the tagged pointer should have
 * @return A tagged pointer, or `nil` if it could not be created
 */
extern id _Nullable objc_createTaggedPointer(int class, uintptr_t value);

/*
 * Used by the compiler, but can also be called manually.
 *
 * These declarations are also required to prevent Clang's implicit
 * declarations which include __declspec(dllimport) on Windows.