ObjFW  Diff

#import "private.h"

#define TAGGED_POINTER_BITS 4
#define NUM_TAGGED_POINTER_CLASSES (1 << (TAGGED_POINTER_BITS - 1))

Class objc_tagged_pointer_classes[NUM_TAGGED_POINTER_CLASSES];
static uint_fast8_t taggedPointerClassesCount;

int_fast8_t
objc_registerTaggedPointerClass(Class class)
{
	uint_fast8_t i;

	objc_global_mutex_lock();

	if (taggedPointerClassesCount == NUM_TAGGED_POINTER_CLASSES) {
		objc_global_mutex_unlock();
		return -1;
	}

	pointer >>= TAGGED_POINTER_BITS;

	return pointer;
}

id
objc_createTaggedPointer(uint_fast8_t class, uintptr_t value)
{
	uintptr_t pointer;

	if (class >= NUM_TAGGED_POINTER_CLASSES)
		return nil;

	if (value > (UINTPTR_MAX >> TAGGED_POINTER_BITS))
		return nil;

	pointer = (class << 1) | 1;
	pointer |= (value << TAGGED_POINTER_BITS);

	return (id)pointer;
}