ObjFW  Artifact [3718c4ff22]

Artifact 3718c4ff224a58be7b6274f9e73e976cd08a1b7debbaf2050fafc37806c0f4f9:

• File src/OFObject.m — part of check-in [6e357d636d] at 2009-10-19 08:29:45 on branch trunk — Fix a bug in -[freeMemory:].

  This could be an out of bounds write if the last element is free'd,
  as i is pointing to the last element then, which does not exist then
  anymore, as it was already resized. Now, it is set before resizing.

  Additionally, if the realloc to make it smaller fails, we just ignore
  that now - it will still work, as we set the correct size before
  resizing. (user: js, size: 11011) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008 - 2009
 *   Jonathan Schleifer <js@webkeks.org>
 *
 * All rights reserved.
 *
 * This file is part of libobjfw. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE included in
 * the packaging of this file.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <assert.h>

#import "OFObject.h"
#import "OFAutoreleasePool.h"
#import "OFExceptions.h"
#import "OFMacros.h"

#import <objc/objc-api.h>
#ifdef __objc_INCLUDE_GNU
#import <objc/sarray.h>
#else
#import <objc/runtime.h>
#endif

struct pre_ivar {
	void   **memchunks;
	size_t memchunks_size;
	size_t retain_count;
};

/* Hopefully no arch needs more than 16 bytes padding */
#define PRE_IVAR_ALIGN ((sizeof(struct pre_ivar) + 15) & ~15)
#define PRE_IVAR ((struct pre_ivar*)((char*)self - PRE_IVAR_ALIGN))

static struct {
	Class isa;
} alloc_failed_exception;

#ifdef NEED_OBJC_SYNC_INIT
extern BOOL objc_sync_init();
#endif

@implementation OFObject
+ (void)initialize
{
#ifdef NEED_OBJC_SYNC_INIT
	if (!objc_sync_init()) {
		fputs("Runtime error: objc_sync_init() failed!\n", stderr);
		abort();
	}
#endif
}

+ alloc
{
	OFObject *instance;
#ifdef __objc_INCLUDE_GNU
	size_t isize = class_get_instance_size(self);
#else
	size_t isize = class_getInstanceSize(self);
#endif

	if ((instance = malloc(isize + PRE_IVAR_ALIGN)) == NULL) {
		alloc_failed_exception.isa = [OFAllocFailedException class];
		@throw (OFAllocFailedException*)&alloc_failed_exception;
	}

	((struct pre_ivar*)instance)->memchunks = NULL;
	((struct pre_ivar*)instance)->memchunks_size = 0;
	((struct pre_ivar*)instance)->retain_count = 1;

	instance = (OFObject*)((char*)instance + PRE_IVAR_ALIGN);
	memset(instance, 0, isize);
	instance->isa = self;

	return instance;
}

+ (Class)class
{
	return self;
}

+ (const char*)className
{
#ifdef __objc_INCLUDE_GNU
	return class_get_class_name(self);
#else
	return class_getName(self);
#endif
}

+ (BOOL)instancesRespondToSelector: (SEL)selector
{
#ifdef __objc_INCLUDE_GNU
	return class_get_instance_method(self, selector) != METHOD_NULL;
#else
	return class_respondsToSelector(self, selector);
#endif
}

+ (BOOL)conformsToProtocol: (Protocol*)protocol
{
#ifdef __objc_INCLUDE_GNU
	Class c;
	struct objc_protocol_list *pl;
	size_t i;

	for (c = self; c != Nil; c = class_get_super_class(c))
		for (pl = c->protocols; pl != NULL; pl = pl->next)
			for (i = 0; i < pl->count; i++)
				if ([pl->list[i] conformsToProtocol: protocol])
					return YES;

	return NO;
#else
	Class c;

	for (c = self; c != Nil; c = class_getSuperclass(c))
		if (class_conformsToProtocol(c, protocol))
			return YES;

	return NO;
#endif
}

+ (IMP)instanceMethodForSelector: (SEL)selector
{
#ifdef __objc_INCLUDE_GNU
	return method_get_imp(class_get_instance_method(self, selector));
#else
	return class_getMethodImplementation(self, selector);
#endif
}

+ (IMP)setImplementation: (IMP)newimp
	       forMethod: (SEL)selector
{
#ifdef __objc_INCLUDE_GNU
	Method_t method = class_get_instance_method(self, selector);
	IMP oldimp;

	if (method == NULL)
		@throw [OFInvalidArgumentException newWithClass: self
						       selector: _cmd];

	if ((oldimp = method_get_imp(method)) == (IMP)0 || newimp == (IMP)0)
		@throw [OFInvalidArgumentException newWithClass: self
						       selector: _cmd];

	method->method_imp = newimp;

	/* Update the dtable if necessary */
	if (sarray_get_safe(((Class)self)->dtable,
	    (sidx)method->method_name->sel_id))
		sarray_at_put_safe(((Class)self)->dtable,
		    (sidx)method->method_name->sel_id, method->method_imp);

	return oldimp;
#else
	Method method;

	if ((method = class_getInstanceMethod(self, selector)) == NULL)
		@throw [OFInvalidArgumentException newWithClass: self
						       selector: _cmd];

	return method_setImplementation(method, newimp);
#endif
}

+  (IMP)replaceMethod: (SEL)selector
  withMethodFromClass: (Class)class;
{
	IMP newimp;

#ifdef __objc_INCLUDE_GNU
	newimp = method_get_imp(class_get_instance_method(class, selector));
#else
	newimp = class_getMethodImplementation(class, selector);
#endif

	return [self setImplementation: newimp
			     forMethod: selector];
}

- init
{
	return self;
}

- (Class)class
{
	return isa;
}

- (const char*)className
{
#ifdef __objc_INCLUDE_GNU
	return object_get_class_name(self);
#else
	return class_getName(isa);
#endif
}

- (BOOL)isKindOfClass: (Class)class
{
	Class iter;

#ifdef __objc_INCLUDE_GNU
	for (iter = isa; iter != Nil; iter = class_get_super_class(iter))
#else
	for (iter = isa; iter != Nil; iter = class_getSuperclass(iter))
#endif
		if (iter == class)
			return YES;

	return NO;
}

- (BOOL)respondsToSelector: (SEL)selector
{
#ifdef __objc_INCLUDE_GNU
	if (object_is_instance(self))
		return class_get_instance_method(isa, selector) != METHOD_NULL;
	else
		return class_get_class_method(isa, selector) != METHOD_NULL;
#else
	return class_respondsToSelector(isa, selector);
#endif
}

- (BOOL)conformsToProtocol: (Protocol*)protocol
{
	return [isa conformsToProtocol: protocol];
}

- (IMP)methodForSelector: (SEL)selector
{
#ifdef __objc_INCLUDE_GNU
	if (object_is_instance(self))
		return method_get_imp(class_get_instance_method(isa, selector));
	else
		return method_get_imp(class_get_class_method(isa, selector));
#else
	return class_getMethodImplementation(isa, selector);
#endif
}

- (BOOL)isEqual: (id)obj
{
	/* Classes containing data should reimplement this! */
	return (self == obj ? YES : NO);
}

- (uint32_t)hash
{
	/* Classes containing data should reimplement this! */
	return (uint32_t)(intptr_t)self;
}

- addMemoryToPool: (void*)ptr
{
	void **memchunks;
	size_t memchunks_size;

	memchunks_size = PRE_IVAR->memchunks_size + 1;

	if (SIZE_MAX - PRE_IVAR->memchunks_size < 1 ||
	    memchunks_size > SIZE_MAX / sizeof(void*))
		@throw [OFOutOfRangeException newWithClass: isa];

	if ((memchunks = realloc(PRE_IVAR->memchunks,
	    memchunks_size * sizeof(void*))) == NULL)
		@throw [OFOutOfMemoryException newWithClass: isa
						       size: memchunks_size];

	PRE_IVAR->memchunks = memchunks;
	PRE_IVAR->memchunks[PRE_IVAR->memchunks_size] = ptr;
	PRE_IVAR->memchunks_size = memchunks_size;

	return self;
}

- (void*)allocMemoryWithSize: (size_t)size
{
	void *ptr, **memchunks;
	size_t memchunks_size;

	if (size == 0)
		return NULL;

	memchunks_size = PRE_IVAR->memchunks_size + 1;

	if (SIZE_MAX - PRE_IVAR->memchunks_size == 0 ||
	    memchunks_size > SIZE_MAX / sizeof(void*))
		@throw [OFOutOfRangeException newWithClass: isa];

	if ((ptr = malloc(size)) == NULL)
		@throw [OFOutOfMemoryException newWithClass: isa
						       size: size];

	if ((memchunks = realloc(PRE_IVAR->memchunks,
	    memchunks_size * sizeof(void*))) == NULL) {
		free(ptr);
		@throw [OFOutOfMemoryException newWithClass: isa
						       size: memchunks_size];
	}

	PRE_IVAR->memchunks = memchunks;
	PRE_IVAR->memchunks[PRE_IVAR->memchunks_size] = ptr;
	PRE_IVAR->memchunks_size = memchunks_size;

	return ptr;
}

- (void*)allocMemoryForNItems: (size_t)nitems
		     withSize: (size_t)size
{
	if (nitems == 0 || size == 0)
		return NULL;

	if (nitems > SIZE_MAX / size)
		@throw [OFOutOfRangeException newWithClass: isa];

	return [self allocMemoryWithSize: nitems * size];
}

- (void*)resizeMemory: (void*)ptr
	       toSize: (size_t)size
{
	void **iter;

	if (ptr == NULL)
		return [self allocMemoryWithSize: size];

	if (size == 0) {
		[self freeMemory: ptr];
		return NULL;
	}

	iter = PRE_IVAR->memchunks + PRE_IVAR->memchunks_size;

	while (iter-- > PRE_IVAR->memchunks) {
		if (OF_UNLIKELY(*iter == ptr)) {
			if (OF_UNLIKELY((ptr = realloc(ptr, size)) == NULL))
				@throw [OFOutOfMemoryException
				    newWithClass: isa
					    size: size];

			*iter = ptr;
			return ptr;
		}
	}

	@throw [OFMemoryNotPartOfObjectException newWithClass: isa
						      pointer: ptr];
}

- (void*)resizeMemory: (void*)ptr
	     toNItems: (size_t)nitems
	     withSize: (size_t)size
{
	if (ptr == NULL)
		return [self allocMemoryForNItems: nitems
					 withSize: size];

	if (nitems == 0 || size == 0) {
		[self freeMemory: ptr];
		return NULL;
	}

	if (nitems > SIZE_MAX / size)
		@throw [OFOutOfRangeException newWithClass: isa];

	return [self resizeMemory: ptr
			   toSize: nitems * size];
}

- freeMemory: (void*)ptr;
{
	void **iter, *last, **memchunks;
	size_t i, memchunks_size;

	iter = PRE_IVAR->memchunks + PRE_IVAR->memchunks_size;
	i = PRE_IVAR->memchunks_size;

	while (iter-- > PRE_IVAR->memchunks) {
		i--;

		if (OF_UNLIKELY(*iter == ptr)) {
			memchunks_size = PRE_IVAR->memchunks_size - 1;
			last = PRE_IVAR->memchunks[memchunks_size];

			assert(PRE_IVAR->memchunks_size != 0 &&
			    memchunks_size <= SIZE_MAX / sizeof(void*));

			if (OF_UNLIKELY(memchunks_size == 0)) {
				free(ptr);
				free(PRE_IVAR->memchunks);

				PRE_IVAR->memchunks = NULL;
				PRE_IVAR->memchunks_size = 0;

				return self;
			}

			free(ptr);
			PRE_IVAR->memchunks[i] = last;
			PRE_IVAR->memchunks_size = memchunks_size;

			if (OF_UNLIKELY((memchunks = realloc(
			    PRE_IVAR->memchunks, memchunks_size *
			    sizeof(void*))) == NULL))
				return self;

			PRE_IVAR->memchunks = memchunks;

			return self;
		}
	}

	@throw [OFMemoryNotPartOfObjectException newWithClass: isa
						      pointer: ptr];
}

- retain
{
	PRE_IVAR->retain_count++;

	return self;
}

- (size_t)retainCount
{
	return PRE_IVAR->retain_count;
}

- (void)release
{
	if (!--PRE_IVAR->retain_count)
		[self dealloc];
}

- autorelease
{
	[OFAutoreleasePool addObjectToTopmostPool: self];

	return self;
}

- (void)dealloc
{
	void **iter = PRE_IVAR->memchunks + PRE_IVAR->memchunks_size;

	while (iter-- > PRE_IVAR->memchunks)
		free(*iter);

	if (PRE_IVAR->memchunks != NULL)
		free(PRE_IVAR->memchunks);

	free((char*)self - PRE_IVAR_ALIGN);
}

/*
 * Those are needed as the root class is the superclass of the root class's
 * metaclass and thus instance methods can be sent to class objects as well.
 */
+ addMemoryToPool: (void*)ptr
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ (void*)allocMemoryWithSize: (size_t)size
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ (void*)allocMemoryForNItems: (size_t)nitems
                     withSize: (size_t)size
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ (void*)resizeMemory: (void*)ptr
	       toSize: (size_t)size
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ (void*)resizeMemory: (void*)ptr
	     toNItems: (size_t)nitems
	     withSize: (size_t)size
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ freeMemory: (void*)ptr
{
	@throw [OFNotImplementedException newWithClass: self
					      selector: _cmd];
}

+ retain
{
	return self;
}

+ autorelease
{
	return self;
}

+ (size_t)retainCount
{
	return SIZE_MAX;
}

+ (void)release
{
}

+ (void)dealloc
{
}
@end