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- /****************************************************************************
- * 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 */
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