/* GNU Objective C Runtime nil receiver function Copyright (C) 1993, 1995, 1996, 2002, 2009 Free Software Foundation, Inc. Contributed by Kresten Krab Thorup 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/>. */ /* This is the nil method, the function that is called when the receiver of a method is nil */ #include "objc/runtime.h" /* When the receiver of a method invocation is nil, the runtime returns nil_method() as the method implementation. This function will be casted to whatever function was supposed to be executed to execute that method (that function will take an id, followed by a SEL, followed by who knows what arguments, depends on the method), and executed. For this reason, nil_method() should be a function which can be called in place of any function taking an 'id' argument followed by a 'SEL' argument, followed by zero, or one, or any number of arguments (both a fixed number, or a variable number !). There is no "proper" implementation of such a nil_method function in C, however in all existing implementations it does not matter when extra arguments are present, so we can simply create a function taking a receiver and a selector, and all other arguments will be ignored. :-) */ id nil_method (id receiver, SEL op __attribute__ ((__unused__))) { return receiver; }