summaryrefslogtreecommitdiff
path: root/libobjc/nil_method.c
diff options
context:
space:
mode:
authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /libobjc/nil_method.c
downloadcbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.bz2
cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.xz
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository.
Diffstat (limited to 'libobjc/nil_method.c')
-rw-r--r--libobjc/nil_method.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/libobjc/nil_method.c b/libobjc/nil_method.c
new file mode 100644
index 000000000..15e3d528c
--- /dev/null
+++ b/libobjc/nil_method.c
@@ -0,0 +1,56 @@
+/* GNU Objective C Runtime nil receiver function
+ Copyright (C) 1993, 1995, 1996, 2002, 2009, 2010
+ 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 3, 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.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+
+/* This is the nil method, the function that is called when the receiver
+ of a method is nil */
+
+#include "objc-private/common.h"
+#include "objc/objc.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;
+}