1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
/* GNU Objective C Runtime nil receiver function
Copyright (C) 1993, 1995, 1996, 2002 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 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, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, 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. */
/* This is the nil method, the function that is called when the receiver
of a method is nil */
#include "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;
}
|
