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 #include <linux/compiler_types.h>
6
7 #ifndef __always_inline
8 #define __always_inline inline
9 #endif
10
11 /**
12 * __struct_group() - Create a mirrored named and anonyomous struct
13 *
14 * @TAG: The tag name for the named sub-struct (usually empty)
15 * @NAME: The identifier name of the mirrored sub-struct
16 * @ATTRS: Any struct attributes (usually empty)
17 * @MEMBERS: The member declarations for the mirrored structs
18 *
19 * Used to create an anonymous union of two structs with identical layout
20 * and size: one anonymous and one named. The former's members can be used
21 * normally without sub-struct naming, and the latter can be used to
22 * reason about the start, end, and size of the group of struct members.
23 * The named struct can also be explicitly tagged for layer reuse, as well
24 * as both having struct attributes appended.
25 */
26 #define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
27 union { \
28 struct { MEMBERS } ATTRS; \
29 struct TAG { MEMBERS } ATTRS NAME; \
30 } ATTRS
31
32 #ifdef __cplusplus
33 /* sizeof(struct{}) is 1 in C++, not 0, can't use C version of the macro. */
34 #define __DECLARE_FLEX_ARRAY(T, member) \
35 T member[0]
36 #else
37 /**
38 * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union
39 *
40 * @TYPE: The type of each flexible array element
41 * @NAME: The name of the flexible array member
42 *
43 * In order to have a flexible array member in a union or alone in a
44 * struct, it needs to be wrapped in an anonymous struct with at least 1
45 * named member, but that member can be empty.
46 */
47 #define __DECLARE_FLEX_ARRAY(TYPE, NAME) \
48 struct { \
49 struct { } __empty_ ## NAME; \
50 TYPE NAME[]; \
51 }
52 #endif
53
54 #ifndef __counted_by
55 #define __counted_by(m)
56 #endif
57
58 #ifndef __counted_by_le
59 #define __counted_by_le(m)
60 #endif
61
62 #ifndef __counted_by_be
63 #define __counted_by_be(m)
64 #endif
65
66 #endif /* _UAPI_LINUX_STDDEF_H */
67
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.