ObjFW  Documentation

/*
 * Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3.0 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * version 3.0 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3.0 along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>

#import "ObjFWRT.h"
#import "private.h"

#ifdef OF_HAVE_THREADS
# import "OFPlainMutex.h"
# define numSpinlocks 8	/* needs to be a power of 2 */
static OFSpinlock spinlocks[numSpinlocks];

static OF_INLINE size_t
spinlockSlot(const void *ptr)
{
	return ((size_t)((uintptr_t)ptr >> 4) & (numSpinlocks - 1));
}

OF_CONSTRUCTOR()
{
	for (size_t i = 0; i < numSpinlocks; i++)
		if (OFSpinlockNew(&spinlocks[i]) != 0)
			OBJC_ERROR("Failed to create spinlocks!");
}
#endif

id
objc_getProperty(id self, SEL _cmd, ptrdiff_t offset, bool atomic)
{
	if (atomic) {
		id *ptr = (id *)(void *)((char *)self + offset);
#ifdef OF_HAVE_THREADS
		size_t slot = spinlockSlot(ptr);

		if (OFSpinlockLock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to lock spinlock!");
		@try {
			return [[*ptr retain] autorelease];
		} @finally {
			if (OFSpinlockUnlock(&spinlocks[slot]) != 0)
				OBJC_ERROR("Failed to unlock spinlock!");
		}
#else
		return [[*ptr retain] autorelease];
#endif
	}

	return *(id *)(void *)((char *)self + offset);
}

void
objc_setProperty(id self, SEL _cmd, ptrdiff_t offset, id value, bool atomic,
    signed char copy)
{
	if (atomic) {
		id *ptr = (id *)(void *)((char *)self + offset);
#ifdef OF_HAVE_THREADS
		size_t slot = spinlockSlot(ptr);

		if (OFSpinlockLock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to lock spinlock!");
		@try {
#endif
			id old = *ptr;

			switch (copy) {
			case 0:
				*ptr = [value retain];
				break;
			case 2:
				*ptr = [value mutableCopy];
				break;
			default:
				*ptr = [value copy];
			}

			[old release];
#ifdef OF_HAVE_THREADS
		} @finally {
			if (OFSpinlockUnlock(&spinlocks[slot]) != 0)
				OBJC_ERROR("Failed to unlock spinlock!");
		}
#endif

		return;
	}

	id *ptr = (id *)(void *)((char *)self + offset);
	id old = *ptr;

	switch (copy) {
	case 0:
		*ptr = [value retain];
		break;
	case 2:
		*ptr = [value mutableCopy];
		break;
	default:
		*ptr = [value copy];
	}

	[old release];
}

/* The following methods are only required for GCC >= 4.6 */
void
objc_getPropertyStruct(void *dest, const void *src, ptrdiff_t size, bool atomic,
    bool strong)
{
	if (atomic) {
#ifdef OF_HAVE_THREADS
		size_t slot = spinlockSlot(src);

		if (OFSpinlockLock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to lock spinlock!");
#endif
		memcpy(dest, src, size);
#ifdef OF_HAVE_THREADS
		if (OFSpinlockUnlock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to unlock spinlock!");
#endif

		return;
	}

	memcpy(dest, src, size);
}

void
objc_setPropertyStruct(void *dest, const void *src, ptrdiff_t size, bool atomic,
    bool strong)
{
	if (atomic) {
#ifdef OF_HAVE_THREADS
		size_t slot = spinlockSlot(src);

		if (OFSpinlockLock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to lock spinlock!");
#endif
		memcpy(dest, src, size);
#ifdef OF_HAVE_THREADS
		if (OFSpinlockUnlock(&spinlocks[slot]) != 0)
			OBJC_ERROR("Failed to unlock spinlock!");
#endif

		return;
	}

	memcpy(dest, src, size);
}

objc_property_t *
class_copyPropertyList(Class class, unsigned int *outCount)
{
	unsigned int i, count;
	struct objc_property_list *iter;
	objc_property_t *properties;

	if (class == Nil) {
		if (outCount != NULL)
			*outCount = 0;

		return NULL;
	}

	objc_globalMutex_lock();

	count = 0;
	if (class->info & OBJC_CLASS_INFO_NEW_ABI)
		for (iter = class->propertyList; iter != NULL;
		    iter = iter->next)
			count += iter->count;

	if (count == 0) {
		if (outCount != NULL)
			*outCount = 0;

		objc_globalMutex_unlock();
		return NULL;
	}

	properties = malloc((count + 1) * sizeof(objc_property_t));
	if (properties == NULL)
		OBJC_ERROR("Not enough memory to copy properties");

	i = 0;
	for (iter = class->propertyList; iter != NULL; iter = iter->next)
		for (unsigned int j = 0; j < iter->count; j++)
			properties[i++] = &iter->properties[j];

	if (i != count)
		OBJC_ERROR("Fatal internal inconsistency!");

	properties[count] = NULL;

	if (outCount != NULL)
		*outCount = count;

	objc_globalMutex_unlock();

	return properties;
}

const char *
property_getName(objc_property_t property)
{
	return property->name;
}

char *
property_copyAttributeValue(objc_property_t property, const char *name)
{
	char *ret = NULL;
	bool nullIsError = false;

	if (strlen(name) != 1)
		return NULL;

	switch (*name) {
	case 'T':
		ret = objc_strdup(property->getter.typeEncoding);
		nullIsError = true;
		break;
	case 'G':
		if (property->attributes & OBJC_PROPERTY_GETTER) {
			ret = objc_strdup(property->getter.name);
			nullIsError = true;
		}
		break;
	case 'S':
		if (property->attributes & OBJC_PROPERTY_SETTER) {
			ret = objc_strdup(property->setter.name);
			nullIsError = true;
		}
		break;
#define BOOL_CASE(name, field, flag)		\
	case name:				\
		if (property->field & flag) {	\
			ret = calloc(1, 1);	\
			nullIsError = true;	\
		}				\
		break;

	BOOL_CASE('R', attributes, OBJC_PROPERTY_READONLY)
	BOOL_CASE('C', attributes, OBJC_PROPERTY_COPY)
	BOOL_CASE('&', attributes, OBJC_PROPERTY_RETAIN)
	BOOL_CASE('N', attributes, OBJC_PROPERTY_NONATOMIC)
	BOOL_CASE('D', extendedAttributes, OBJC_PROPERTY_DYNAMIC)
	BOOL_CASE('W', extendedAttributes, OBJC_PROPERTY_WEAK)
#undef BOOL_CASE
	}

	if (nullIsError && ret == NULL)
		OBJC_ERROR("Not enough memory to copy property attribute "
		    "value!");

	return ret;
}