16f52b16cSGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 255037ed7STadeusz Struk #ifndef _UAPI_LINUX_STDDEF_H 355037ed7STadeusz Struk #define _UAPI_LINUX_STDDEF_H 455037ed7STadeusz Struk 5d1515582SWill Deacon #include <linux/compiler_types.h> 6283d7573SDenys Vlasenko 7283d7573SDenys Vlasenko #ifndef __always_inline 8283d7573SDenys Vlasenko #define __always_inline inline 9283d7573SDenys Vlasenko #endif 1050d7bd38SKees Cook 1150d7bd38SKees Cook /** 1250d7bd38SKees Cook * __struct_group() - Create a mirrored named and anonyomous struct 1350d7bd38SKees Cook * 1450d7bd38SKees Cook * @TAG: The tag name for the named sub-struct (usually empty) 1550d7bd38SKees Cook * @NAME: The identifier name of the mirrored sub-struct 1650d7bd38SKees Cook * @ATTRS: Any struct attributes (usually empty) 1750d7bd38SKees Cook * @MEMBERS: The member declarations for the mirrored structs 1850d7bd38SKees Cook * 1950d7bd38SKees Cook * Used to create an anonymous union of two structs with identical layout 2050d7bd38SKees Cook * and size: one anonymous and one named. The former's members can be used 2150d7bd38SKees Cook * normally without sub-struct naming, and the latter can be used to 2250d7bd38SKees Cook * reason about the start, end, and size of the group of struct members. 2350d7bd38SKees Cook * The named struct can also be explicitly tagged for layer reuse, as well 2450d7bd38SKees Cook * as both having struct attributes appended. 2550d7bd38SKees Cook */ 2650d7bd38SKees Cook #define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \ 2750d7bd38SKees Cook union { \ 2850d7bd38SKees Cook struct { MEMBERS } ATTRS; \ 2950d7bd38SKees Cook struct TAG { MEMBERS } ATTRS NAME; \ 3050d7bd38SKees Cook } 313080ea55SKees Cook 32*32a4ec21SAlexey Dobriyan #ifdef __cplusplus 33*32a4ec21SAlexey Dobriyan /* sizeof(struct{}) is 1 in C++, not 0, can't use C version of the macro. */ 34*32a4ec21SAlexey Dobriyan #define __DECLARE_FLEX_ARRAY(T, member) \ 35*32a4ec21SAlexey Dobriyan T member[0] 36*32a4ec21SAlexey Dobriyan #else 373080ea55SKees Cook /** 383080ea55SKees Cook * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union 393080ea55SKees Cook * 403080ea55SKees Cook * @TYPE: The type of each flexible array element 413080ea55SKees Cook * @NAME: The name of the flexible array member 423080ea55SKees Cook * 433080ea55SKees Cook * In order to have a flexible array member in a union or alone in a 443080ea55SKees Cook * struct, it needs to be wrapped in an anonymous struct with at least 1 453080ea55SKees Cook * named member, but that member can be empty. 463080ea55SKees Cook */ 473080ea55SKees Cook #define __DECLARE_FLEX_ARRAY(TYPE, NAME) \ 483080ea55SKees Cook struct { \ 493080ea55SKees Cook struct { } __empty_ ## NAME; \ 503080ea55SKees Cook TYPE NAME[]; \ 513080ea55SKees Cook } 52*32a4ec21SAlexey Dobriyan #endif 53c8248fafSKees Cook 54c8248fafSKees Cook #ifndef __counted_by 55c8248fafSKees Cook #define __counted_by(m) 56c8248fafSKees Cook #endif 57531108ecSAlexey Dobriyan 58531108ecSAlexey Dobriyan #endif /* _UAPI_LINUX_STDDEF_H */ 59