openssl/include/internal/endian.h
Matt Caswell da1c088f59 Copyright year updates
Reviewed-by: Richard Levitte <levitte@openssl.org>
Release: yes
2023-09-07 09:59:15 +01:00

52 lines
1.8 KiB
C

/*
* Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#ifndef OSSL_INTERNAL_ENDIAN_H
# define OSSL_INTERNAL_ENDIAN_H
# pragma once
/*
* IS_LITTLE_ENDIAN and IS_BIG_ENDIAN can be used to detect the endianness
* at compile time. To use it, DECLARE_IS_ENDIAN must be used to declare
* a variable.
*
* L_ENDIAN and B_ENDIAN can be used at preprocessor time. They can be set
* in the configarion using the lib_cppflags variable. If neither is
* set, it will fall back to code works with either endianness.
*/
# if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__)
# define DECLARE_IS_ENDIAN const int ossl_is_little_endian = __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
# define IS_LITTLE_ENDIAN (ossl_is_little_endian)
# define IS_BIG_ENDIAN (!ossl_is_little_endian)
# if defined(L_ENDIAN) && (__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__)
# error "L_ENDIAN defined on a big endian machine"
# endif
# if defined(B_ENDIAN) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
# error "B_ENDIAN defined on a little endian machine"
# endif
# if !defined(L_ENDIAN) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
# define L_ENDIAN
# endif
# if !defined(B_ENDIAN) && (__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__)
# define B_ENDIAN
# endif
# else
# define DECLARE_IS_ENDIAN \
const union { \
long one; \
char little; \
} ossl_is_endian = { 1 }
# define IS_LITTLE_ENDIAN (ossl_is_endian.little != 0)
# define IS_BIG_ENDIAN (ossl_is_endian.little == 0)
# endif
#endif