Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_STDDEF_H |
3 | #define _LINUX_STDDEF_H | |
4 | ||
607ca46e | 5 | #include <uapi/linux/stddef.h> |
1da177e4 LT |
6 | |
7 | #undef NULL | |
1da177e4 | 8 | #define NULL ((void *)0) |
6e218287 RK |
9 | |
10 | enum { | |
11 | false = 0, | |
12 | true = 1 | |
13 | }; | |
14 | ||
1da177e4 | 15 | #undef offsetof |
14e83077 | 16 | #define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER) |
38764884 | 17 | |
4229a470 | 18 | /** |
e7f18c22 | 19 | * sizeof_field() - Report the size of a struct field in bytes |
4229a470 KC |
20 | * |
21 | * @TYPE: The structure containing the field of interest | |
22 | * @MEMBER: The field to return the size of | |
23 | */ | |
24 | #define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) | |
25 | ||
38764884 | 26 | /** |
e7f18c22 | 27 | * offsetofend() - Report the offset of a struct field within the struct |
38764884 DV |
28 | * |
29 | * @TYPE: The type of the structure | |
30 | * @MEMBER: The member within the structure to get the end offset of | |
31 | */ | |
32 | #define offsetofend(TYPE, MEMBER) \ | |
4229a470 | 33 | (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) |
8c7fbe57 | 34 | |
50d7bd38 KC |
35 | /** |
36 | * struct_group() - Wrap a set of declarations in a mirrored struct | |
37 | * | |
38 | * @NAME: The identifier name of the mirrored sub-struct | |
39 | * @MEMBERS: The member declarations for the mirrored structs | |
40 | * | |
41 | * Used to create an anonymous union of two structs with identical | |
42 | * layout and size: one anonymous and one named. The former can be | |
43 | * used normally without sub-struct naming, and the latter can be | |
44 | * used to reason about the start, end, and size of the group of | |
45 | * struct members. | |
46 | */ | |
47 | #define struct_group(NAME, MEMBERS...) \ | |
48 | __struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS) | |
49 | ||
50 | /** | |
51 | * struct_group_attr() - Create a struct_group() with trailing attributes | |
52 | * | |
53 | * @NAME: The identifier name of the mirrored sub-struct | |
54 | * @ATTRS: Any struct attributes to apply | |
55 | * @MEMBERS: The member declarations for the mirrored structs | |
56 | * | |
57 | * Used to create an anonymous union of two structs with identical | |
58 | * layout and size: one anonymous and one named. The former can be | |
59 | * used normally without sub-struct naming, and the latter can be | |
60 | * used to reason about the start, end, and size of the group of | |
61 | * struct members. Includes structure attributes argument. | |
62 | */ | |
63 | #define struct_group_attr(NAME, ATTRS, MEMBERS...) \ | |
64 | __struct_group(/* no tag */, NAME, ATTRS, MEMBERS) | |
65 | ||
66 | /** | |
67 | * struct_group_tagged() - Create a struct_group with a reusable tag | |
68 | * | |
69 | * @TAG: The tag name for the named sub-struct | |
70 | * @NAME: The identifier name of the mirrored sub-struct | |
71 | * @MEMBERS: The member declarations for the mirrored structs | |
72 | * | |
73 | * Used to create an anonymous union of two structs with identical | |
74 | * layout and size: one anonymous and one named. The former can be | |
75 | * used normally without sub-struct naming, and the latter can be | |
76 | * used to reason about the start, end, and size of the group of | |
77 | * struct members. Includes struct tag argument for the named copy, | |
78 | * so the specified layout can be reused later. | |
79 | */ | |
80 | #define struct_group_tagged(TAG, NAME, MEMBERS...) \ | |
81 | __struct_group(TAG, NAME, /* no attrs */, MEMBERS) | |
82 | ||
3080ea55 KC |
83 | /** |
84 | * DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union | |
85 | * | |
86 | * @TYPE: The type of each flexible array element | |
87 | * @NAME: The name of the flexible array member | |
88 | * | |
89 | * In order to have a flexible array member in a union or alone in a | |
90 | * struct, it needs to be wrapped in an anonymous struct with at least 1 | |
91 | * named member, but that member can be empty. | |
92 | */ | |
93 | #define DECLARE_FLEX_ARRAY(TYPE, NAME) \ | |
94 | __DECLARE_FLEX_ARRAY(TYPE, NAME) | |
95 | ||
8c7fbe57 | 96 | #endif |