Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2#ifndef _UAPI_LINUX_STDDEF_H
3#define _UAPI_LINUX_STDDEF_H
4
5#ifdef __KERNEL__
6#include <linux/compiler_types.h>
7#endif
8
9#ifndef __always_inline
10#define __always_inline inline
11#endif
12
13/* Not all C++ standards support type declarations inside an anonymous union */
14#ifndef __cplusplus
15#define __struct_group_tag(TAG) TAG
16#else
17#define __struct_group_tag(TAG)
18#endif
19
20/**
21 * __struct_group() - Create a mirrored named and anonyomous struct
22 *
23 * @TAG: The tag name for the named sub-struct (usually empty)
24 * @NAME: The identifier name of the mirrored sub-struct
25 * @ATTRS: Any struct attributes (usually empty)
26 * @MEMBERS: The member declarations for the mirrored structs
27 *
28 * Used to create an anonymous union of two structs with identical layout
29 * and size: one anonymous and one named. The former's members can be used
30 * normally without sub-struct naming, and the latter can be used to
31 * reason about the start, end, and size of the group of struct members.
32 * The named struct can also be explicitly tagged for layer reuse (C only),
33 * as well as both having struct attributes appended.
34 */
35#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
36 union { \
37 struct { MEMBERS } ATTRS; \
38 struct __struct_group_tag(TAG) { MEMBERS } ATTRS NAME; \
39 } ATTRS
40
41#ifdef __cplusplus
42/* sizeof(struct{}) is 1 in C++, not 0, can't use C version of the macro. */
43#define __DECLARE_FLEX_ARRAY(T, member) \
44 T member[0]
45#else
46/**
47 * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union
48 *
49 * @TYPE: The type of each flexible array element
50 * @NAME: The name of the flexible array member
51 *
52 * In order to have a flexible array member in a union or alone in a
53 * struct, it needs to be wrapped in an anonymous struct with at least 1
54 * named member, but that member can be empty.
55 */
56#define __DECLARE_FLEX_ARRAY(TYPE, NAME) \
57 struct { \
58 struct { } __empty_ ## NAME; \
59 TYPE NAME[]; \
60 }
61#endif
62
63#ifndef __counted_by
64#define __counted_by(m)
65#endif
66
67#ifndef __counted_by_le
68#define __counted_by_le(m)
69#endif
70
71#ifndef __counted_by_be
72#define __counted_by_be(m)
73#endif
74
75#ifdef __KERNEL__
76#define __kernel_nonstring __nonstring
77#else
78#define __kernel_nonstring
79#endif
80
81#endif /* _UAPI_LINUX_STDDEF_H */