diff options
author | Gregory Nutt <gnutt@nuttx.org> | 2014-01-09 15:49:54 -0600 |
---|---|---|
committer | Gregory Nutt <gnutt@nuttx.org> | 2014-01-09 15:49:54 -0600 |
commit | 58635ac9da13fc6cc26043033578417b6d9cfcd0 (patch) | |
tree | cf53d7522bdb3cb6c3bcf1a1780a2263345fc39c | |
parent | aa2b82b4ac938e8335af06fdfadd8a7f7e80843d (diff) | |
download | nuttx-58635ac9da13fc6cc26043033578417b6d9cfcd0.tar.gz nuttx-58635ac9da13fc6cc26043033578417b6d9cfcd0.tar.bz2 nuttx-58635ac9da13fc6cc26043033578417b6d9cfcd0.zip |
Flesh out stddefs.h
-rw-r--r-- | nuttx/include/stddef.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/nuttx/include/stddef.h b/nuttx/include/stddef.h index f08135bf7..dd8385c9f 100644 --- a/nuttx/include/stddef.h +++ b/nuttx/include/stddef.h @@ -43,7 +43,56 @@ #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). + * + * 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 both 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 + */ + +typedef ssize_t ptrdiff_t; #endif /* __INCLUDE_STDDEF_H */ |