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/* This file contains the implementation of class Protocol.
Copyright (C) 1993, 2004, 2009 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC 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 General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "objc-private/common.h"
#include "objc/Protocol.h"
#include "objc/objc-api.h"
/* Method description list */
struct objc_method_description_list {
int count;
struct objc_method_description list[1];
};
@implementation Protocol
{
@private
char *protocol_name;
struct objc_protocol_list *protocol_list;
struct objc_method_description_list *instance_methods, *class_methods;
}
/* Obtaining attributes intrinsic to the protocol */
- (const char *)name
{
return protocol_name;
}
/* Testing protocol conformance */
- (BOOL) conformsTo: (Protocol *)aProtocolObject
{
size_t i;
struct objc_protocol_list* proto_list;
if (aProtocolObject == nil)
return NO;
if (!strcmp(aProtocolObject->protocol_name, self->protocol_name))
return YES;
for (proto_list = protocol_list; proto_list; proto_list = proto_list->next)
{
for (i=0; i < proto_list->count; i++)
{
if ([proto_list->list[i] conformsTo: aProtocolObject])
return YES;
}
}
return NO;
}
/* Looking up information specific to a protocol */
- (struct objc_method_description *) descriptionForInstanceMethod:(SEL)aSel
{
int i;
struct objc_protocol_list* proto_list;
const char* name = sel_get_name (aSel);
struct objc_method_description *result;
if (instance_methods)
for (i = 0; i < instance_methods->count; i++)
{
if (!strcmp ((char*)instance_methods->list[i].name, name))
return &(instance_methods->list[i]);
}
for (proto_list = protocol_list; proto_list; proto_list = proto_list->next)
{
size_t j;
for (j=0; j < proto_list->count; j++)
{
if ((result = [proto_list->list[j]
descriptionForInstanceMethod: aSel]))
return result;
}
}
return NULL;
}
- (struct objc_method_description *) descriptionForClassMethod:(SEL)aSel;
{
int i;
struct objc_protocol_list* proto_list;
const char* name = sel_get_name (aSel);
struct objc_method_description *result;
if (class_methods)
for (i = 0; i < class_methods->count; i++)
{
if (!strcmp ((char*)class_methods->list[i].name, name))
return &(class_methods->list[i]);
}
for (proto_list = protocol_list; proto_list; proto_list = proto_list->next)
{
size_t j;
for (j=0; j < proto_list->count; j++)
{
if ((result = [proto_list->list[j]
descriptionForClassMethod: aSel]))
return result;
}
}
return NULL;
}
- (unsigned) hash
{
/* Compute a hash of the protocol_name; use the same hash algorithm
* that we use for class names; protocol names and class names are
* somewhat similar types of string spaces.
*/
int hash = 0, index;
for (index = 0; protocol_name[index] != '\0'; index++)
{
hash = (hash << 4) ^ (hash >> 28) ^ protocol_name[index];
}
hash = (hash ^ (hash >> 10) ^ (hash >> 20));
return hash;
}
/*
* Equality between formal protocols is only formal (nothing to do
* with actually checking the list of methods they have!). Two formal
* Protocols are equal if and only if they have the same name.
*
* Please note (for comparisons with other implementations) that
* checking the names is equivalent to checking that Protocol A
* conforms to Protocol B and Protocol B conforms to Protocol A,
* because this happens iff they have the same name. If they have
* different names, A conforms to B if and only if A includes B, but
* the situation where A includes B and B includes A is a circular
* dependency between Protocols which is forbidden by the compiler, so
* A conforms to B and B conforms to A with A and B having different
* names is an impossible case.
*/
- (BOOL) isEqual: (id)obj
{
if (obj == self)
return YES;
if ([obj isKindOf: [Protocol class]])
{
if (strcmp (protocol_name, ((Protocol *)obj)->protocol_name) == 0)
return YES;
}
return NO;
}
@end
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