| /* |
| * Copyright 2019-2021 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 endiannes |
| * 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 |