diff options
Diffstat (limited to 'contrib/libobjc/nil_method.c')
| -rw-r--r-- | contrib/libobjc/nil_method.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/contrib/libobjc/nil_method.c b/contrib/libobjc/nil_method.c index 1b62128..5e37c4d 100644 --- a/contrib/libobjc/nil_method.c +++ b/contrib/libobjc/nil_method.c @@ -1,5 +1,5 @@ /* GNU Objective C Runtime nil receiver function - Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc. + Copyright (C) 1993, 1995, 1996, 2002 Free Software Foundation, Inc. Contributed by Kresten Krab Thorup This file is part of GNU CC. @@ -29,12 +29,27 @@ Boston, MA 02111-1307, USA. */ #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, ...) +nil_method (id receiver, SEL op __attribute__ ((__unused__))) { return receiver; } - - - - |
