1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11 
  12 /*
  13  * Copyright 2016 Joyent, Inc.
  14  * Copyright 2023 Oxide Computer Company
  15  */
  16 
  17 #ifndef _SYS_STDALIGN_H
  18 #define _SYS_STDALIGN_H
  19 
  20 /*
  21  * ISO/IEC C11 stdalign.h. This header is meant to provide definitions for the
  22  * alignas and alignof 'keywords' into the underlying compiler-understood value.
  23  * In addition, there are two macros that are meant to define that this process
  24  * has happened. C++11 added alignas/alignof as keywords and including this
  25  * header is meant to cause us to still have the _is_defined macros, but not
  26  * define this overall.
  27  *
  28  * Unlike other cases we don't use any symbol guards here (other than C++) and
  29  * just allow the implementation to either have _Alignas and _Alignof or not
  30  * have it and lead to a compiler error for the user. The main justification of
  31  * this is that this header is only defined in C11 (and newer). It's not defined
  32  * in other standards and just as if you include a non-standard header, in this
  33  * case we don't try to stop that (same as if you included something like
  34  * libdevinfo.h).
  35  */
  36 
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40 
  41 #ifndef __cplusplus
  42 
  43 #define alignas _Alignas
  44 /*CSTYLED*/
  45 #define alignof _Alignof
  46 
  47 #endif  /* !__cplusplus */
  48 
  49 #define __alignas_is_defined    1
  50 #define __alignof_is_defined    1
  51 
  52 #ifdef __cplusplus
  53 }
  54 #endif
  55 
  56 #endif /* _SYS_STDALIGN_H */