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Diffstat (limited to 'contrib/libobjc/nil_method.c')
-rw-r--r-- | contrib/libobjc/nil_method.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/contrib/libobjc/nil_method.c b/contrib/libobjc/nil_method.c new file mode 100644 index 0000000..268f0e3 --- /dev/null +++ b/contrib/libobjc/nil_method.c @@ -0,0 +1,55 @@ +/* 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, 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. */ + +/* 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; +} |