| /* This file contains the implementation of class Protocol. |
| Copyright (C) 1993, 2004 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 2, 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING. If not, write to |
| the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| /* As a special exception, if you link this library with files |
| compiled with GCC to produce an executable, this does not cause |
| the resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why |
| the executable file might be covered by the GNU General Public License. */ |
| |
| #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 |
| |