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56 lines
2.2 KiB
C
56 lines
2.2 KiB
C
/* GNU Objective C Runtime nil receiver function
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Copyright (C) 1993-2020 Free Software Foundation, Inc.
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Contributed by Kresten Krab Thorup
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation; either version 3, or (at your option) any later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* This is the nil method, the function that is called when the receiver
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of a method is nil */
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#include "objc-private/common.h"
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#include "objc/objc.h"
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/* When the receiver of a method invocation is nil, the runtime
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returns nil_method() as the method implementation. This function
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will be casted to whatever function was supposed to be executed to
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execute that method (that function will take an id, followed by a
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SEL, followed by who knows what arguments, depends on the method),
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and executed.
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For this reason, nil_method() should be a function which can be
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called in place of any function taking an 'id' argument followed by
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a 'SEL' argument, followed by zero, or one, or any number of
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arguments (both a fixed number, or a variable number !).
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There is no "proper" implementation of such a nil_method function
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in C, however in all existing implementations it does not matter
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when extra arguments are present, so we can simply create a function
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taking a receiver and a selector, and all other arguments will be
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ignored. :-)
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*/
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id
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nil_method (id receiver, SEL op __attribute__ ((__unused__)))
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{
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return receiver;
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}
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