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6f52b16c | 1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
55037ed7 TS |
2 | #ifndef _UAPI_LINUX_STDDEF_H |
3 | #define _UAPI_LINUX_STDDEF_H | |
4 | ||
d1515582 | 5 | #include <linux/compiler_types.h> |
283d7573 DV |
6 | |
7 | #ifndef __always_inline | |
8 | #define __always_inline inline | |
9 | #endif | |
50d7bd38 KC |
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 | } | |
3080ea55 KC |
31 | |
32 | /** | |
33 | * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union | |
34 | * | |
35 | * @TYPE: The type of each flexible array element | |
36 | * @NAME: The name of the flexible array member | |
37 | * | |
38 | * In order to have a flexible array member in a union or alone in a | |
39 | * struct, it needs to be wrapped in an anonymous struct with at least 1 | |
40 | * named member, but that member can be empty. | |
41 | */ | |
42 | #define __DECLARE_FLEX_ARRAY(TYPE, NAME) \ | |
43 | struct { \ | |
44 | struct { } __empty_ ## NAME; \ | |
45 | TYPE NAME[]; \ | |
46 | } | |
55037ed7 | 47 | #endif |