nuttx/include/stdbool.h
Alin Jerpelea 9b9be7e1f0 include: Author: Gregory Nutt: update licenses to Apache 2.0
Update files from Gregory Nutt to Apache 2.0 license.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-02-04 03:33:58 -08:00

105 lines
3.9 KiB
C

/****************************************************************************
* include/stdbool.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_STDBOOL_H
#define __INCLUDE_STDBOOL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/* If CONFIG_ARCH_STDBOOL_H is set, then the architecture will provide its
* own stdbool.h file. In this case, this header file will simply re-direct
* to the architecture-specfic stdbool.h header file.
*/
#ifdef CONFIG_ARCH_STDBOOL_H
# include <arch/stdbool.h>
/* NuttX will insist that the sizeof(bool) is 8-bits. The sizeof of _Bool
* used by any specific compiler is implementation specific: It can vary from
* compiler-to-compiler and even vary between different versions of the same
* compiler. Compilers seems to be converging to sizeof(_Bool) == 1. If that
* is true for your compiler, you should define CONFIG_C99_BOOL8 in your
* NuttX configuration for better standards compatibility.
*
* CONFIG_C99_BOOL8 - Means (1) your C++ compiler has sizeof(_Bool) == 8,
* (2) your C compiler supports the C99 _Bool intrinsic type, and (3) that
* the C99 _Bool type also has size 1.
*/
#else
/* nuttx/compiler.h may also define or undefine CONFIG_C99_BOOL8 */
# include <nuttx/compiler.h>
# include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* bool, true, and false must be provided as macros so that they can be
* redefined by the application if necessary.
*
* NOTE: Under C99 'bool' is required to be defined to be the intrinsic type
* _Bool. However, in this NuttX context, we need backward compatibility
* to pre-C99 standards where _Bool is not an intrinsic type. Hence, we
* use _Bool8 as the underlying type (unless CONFIG_C99_BOOL8 is defined)
*/
#ifndef __cplusplus
#ifdef CONFIG_C99_BOOL8
# define bool _Bool
#else
# define bool _Bool8
#endif
#define true (bool)1
#define false (bool)0
#define __bool_true_false_are_defined 1
#endif /* __cplusplus */
/****************************************************************************
* Public Types
****************************************************************************/
/* A byte is the smallest address memory element (at least in architectures
* that do not support bit banding). The requirement is only that type _Bool
* be large enough to hold the values 0 and 1. We select uint8_t to minimize
* the RAM footprint of the executable.
*
* NOTE: We can't actually define the type _Bool here. Under C99 _Bool is
* an intrinsic type and cannot be the target of a typedef. However, in this
* NuttX context, we also need backward compatibility to pre-C99 standards
* where _Bool is not an intrinsic type. We work around this by using _Bool8
* as the underlying type.
*/
#ifndef CONFIG_C99_BOOL8
typedef uint8_t _Bool8;
#endif
#endif /* CONFIG_ARCH_STDBOOL_H */
#endif /* __INCLUDE_STDBOOL_H */