| /**************************************************************************** |
| * include/stddef.h |
| * |
| * Copyright (C) 2007-2009 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <gnutt@nuttx.org> |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * 3. Neither the name NuttX nor the names of its contributors may be |
| * used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * |
| ****************************************************************************/ |
| |
| #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 |
| */ |
| |
| #endif /* __INCLUDE_STDDEF_H */ |