xref: /openbmc/linux/include/uapi/linux/stddef.h (revision 50d7bd38)
16f52b16cSGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2d1515582SWill Deacon #include <linux/compiler_types.h>
3283d7573SDenys Vlasenko 
4283d7573SDenys Vlasenko #ifndef __always_inline
5283d7573SDenys Vlasenko #define __always_inline inline
6283d7573SDenys Vlasenko #endif
7*50d7bd38SKees Cook 
8*50d7bd38SKees Cook /**
9*50d7bd38SKees Cook  * __struct_group() - Create a mirrored named and anonyomous struct
10*50d7bd38SKees Cook  *
11*50d7bd38SKees Cook  * @TAG: The tag name for the named sub-struct (usually empty)
12*50d7bd38SKees Cook  * @NAME: The identifier name of the mirrored sub-struct
13*50d7bd38SKees Cook  * @ATTRS: Any struct attributes (usually empty)
14*50d7bd38SKees Cook  * @MEMBERS: The member declarations for the mirrored structs
15*50d7bd38SKees Cook  *
16*50d7bd38SKees Cook  * Used to create an anonymous union of two structs with identical layout
17*50d7bd38SKees Cook  * and size: one anonymous and one named. The former's members can be used
18*50d7bd38SKees Cook  * normally without sub-struct naming, and the latter can be used to
19*50d7bd38SKees Cook  * reason about the start, end, and size of the group of struct members.
20*50d7bd38SKees Cook  * The named struct can also be explicitly tagged for layer reuse, as well
21*50d7bd38SKees Cook  * as both having struct attributes appended.
22*50d7bd38SKees Cook  */
23*50d7bd38SKees Cook #define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
24*50d7bd38SKees Cook 	union { \
25*50d7bd38SKees Cook 		struct { MEMBERS } ATTRS; \
26*50d7bd38SKees Cook 		struct TAG { MEMBERS } ATTRS NAME; \
27*50d7bd38SKees Cook 	}
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