nuttx/include/stddef.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

108 lines
3.8 KiB
C

/****************************************************************************
* include/stddef.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_STDDEF_H
#define __INCLUDE_STDDEF_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* The <stddef.h> header shall define the following macros:
*
* NULL
* The null pointer constant.
*
* NOTE: Currently the definition of NULL is in sys/types.h but should
* be moved here sometime.
*
* offsetof(type, member-designator)
* Integer constant expression of type size_t, the value of which is the
* offset in bytes to the structure member (member-designator), from the
* beginning of its structure (type).
*
* NOTE: This version of offsetof() depends on behaviors that could be
* undefined for some compilers. It would be better to use a builtin
* function if one exists.
*
* Reference: Opengroup.org
*/
#define offsetof(a, b) ((size_t)(&(((a *)(0))->b)))
/****************************************************************************
* Type Definitions
****************************************************************************/
/* The <stddef.h> header shall define the following types:
*
* ptrdiff_t
* Signed integer type of the result of subtracting two pointers.
*
* wchar_t
* Integer type whose range of values can represent distinct wide-character
* codes for all members of the largest character set specified among the
* locales supported by the compilation environment: the null character has
* the code value 0 and each member of the portable character set has a
* code value equal to its value when used as the lone character in an
* integer character constant.
*
* size_t
* Unsigned integer type of the result of the sizeof operator.
*
* NOTE: Currently the type definitions of ptrdiff_t, wchar_t, and size_t are
* in sys/types.h but should be moved here sometime.
*
* The implementation shall support one or more programming environments in
* which the widths of ptrdiff_t, size_t, and wchar_t are no greater than the
* width of type long. The names of these programming environments can be
* obtained using the confstr() function or the getconf utility.
*
* Reference: Opengroup.org
*/
/* Type whose alignment is supported in every context and is at least
* as great as that of any standard type not using alignment specifiers.
*/
typedef struct
{
#if defined(CONFIG_HAVE_LONG_LONG)
long long max_align_i;
#else
long max_align_i;
#endif
#if defined(CONFIG_HAVE_LONG_DOUBLE)
long double max_align_f;
#elif defined(CONFIG_HAVE_DOUBLE)
double max_align_f;
#elif defined(CONFIG_HAVE_FLOAT)
float max_align_f;
#endif
} max_align_t;
#endif /* __INCLUDE_STDDEF_H */