Daily bump.

[pf3gnuchains/gcc-fork.git] / libobjc / nil_method.c

diff --git a/libobjc/nil_method.c b/libobjc/nil_method.c
index 214235b..d35ccdc 100644 (file)
--- a/libobjc/nil_method.c
+++ b/libobjc/nil_method.c
@@ -1,20 +1,20 @@
 /* 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.
+This file is part of GCC.
 
-GNU CC is free software; you can redistribute it and/or modify it under the
+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.
 
-GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY
+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
-GNU CC; see the file COPYING.  If not, write to the Free Software
+GCC; see the file COPYING.  If not, write to the Free Software
 Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
@@ -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 __attribute__ ((__unused__)), ...)
+nil_method (id receiver, SEL op __attribute__ ((__unused__)))
 {
   return receiver;
 }
-
-
-
-