1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 /**
32  * @file bits/ioctl.h
33  * @brief The ioctl() function.
34  */
35 
36 #include <sys/cdefs.h>
37 
38 __BEGIN_DECLS
39 
40 /**
41  * [ioctl(2)](http://man7.org/linux/man-pages/man2/ioctl.2.html) operates on device files.
42  */
43 int ioctl(int __fd, int __request, ...);
44 
45 /*
46  * Work around unsigned -> signed conversion warnings: many common ioctl
47  * constants are unsigned.
48  *
49  * Since this workaround introduces an overload to ioctl, it's possible that it
50  * will break existing code that takes the address of ioctl. If such a breakage
51  * occurs, you can work around it by either:
52  * - specifying a concrete, correct type for ioctl (whether it be through a cast
53  *   in `(int (*)(int, int, ...))ioctl`, creating a temporary variable with the
54  *   type of the ioctl you prefer, ...), or
55  * - defining BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD, which will make the
56  *   overloading go away.
57  */
58 #if !defined(BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD)
59 /* enable_if(1) just exists to break overloading ties. */
60 int ioctl(int __fd, unsigned __request, ...) __overloadable __enable_if(1, "") __RENAME(ioctl);
61 #endif
62 
63 __END_DECLS
64