/* $NetBSD: featuretest.h,v 1.8 2005/12/11 12:25:20 christos Exp $ */ | |
/* | |
* Written by Klaus Klein <kleink@NetBSD.org>, February 2, 1998. | |
* Public domain. | |
* | |
* NOTE: Do not protect this header against multiple inclusion. Doing | |
* so can have subtle side-effects due to header file inclusion order | |
* and testing of e.g. _POSIX_SOURCE vs. _POSIX_C_SOURCE. Instead, | |
* protect each CPP macro that we want to supply. | |
*/ | |
/* | |
* Feature-test macros are defined by several standards, and allow an | |
* application to specify what symbols they want the system headers to | |
* expose, and hence what standard they want them to conform to. | |
* There are two classes of feature-test macros. The first class | |
* specify complete standards, and if one of these is defined, header | |
* files will try to conform to the relevant standard. They are: | |
* | |
* ANSI macros: | |
* _ANSI_SOURCE ANSI C89 | |
* | |
* POSIX macros: | |
* _POSIX_SOURCE == 1 IEEE Std 1003.1 (version?) | |
* _POSIX_C_SOURCE == 1 IEEE Std 1003.1-1990 | |
* _POSIX_C_SOURCE == 2 IEEE Std 1003.2-1992 | |
* _POSIX_C_SOURCE == 199309L IEEE Std 1003.1b-1993 | |
* _POSIX_C_SOURCE == 199506L ISO/IEC 9945-1:1996 | |
* _POSIX_C_SOURCE == 200112L IEEE Std 1003.1-2001 | |
* | |
* X/Open macros: | |
* _XOPEN_SOURCE System Interfaces and Headers, Issue 4, Ver 2 | |
* _XOPEN_SOURCE_EXTENDED == 1 XSH4.2 UNIX extensions | |
* _XOPEN_SOURCE == 500 System Interfaces and Headers, Issue 5 | |
* _XOPEN_SOURCE == 520 Networking Services (XNS), Issue 5.2 | |
* _XOPEN_SOURCE == 600 IEEE Std 1003.1-2001, XSI option | |
* | |
* NetBSD macros: | |
* _NETBSD_SOURCE == 1 Make all NetBSD features available. | |
* | |
* If more than one of these "major" feature-test macros is defined, | |
* then the set of facilities provided (and namespace used) is the | |
* union of that specified by the relevant standards, and in case of | |
* conflict, the earlier standard in the above list has precedence (so | |
* if both _POSIX_C_SOURCE and _NETBSD_SOURCE are defined, the version | |
* of rename() that's used is the POSIX one). If none of the "major" | |
* feature-test macros is defined, _NETBSD_SOURCE is assumed. | |
* | |
* There are also "minor" feature-test macros, which enable extra | |
* functionality in addition to some base standard. They should be | |
* defined along with one of the "major" macros. The "minor" macros | |
* are: | |
* | |
* _REENTRANT | |
* _ISOC99_SOURCE | |
* _LARGEFILE_SOURCE Large File Support | |
* <http://ftp.sas.com/standards/large.file/x_open.20Mar96.html> | |
*/ | |
#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) | |
#define _POSIX_C_SOURCE 1L | |
#endif | |
#if !defined(_ANSI_SOURCE) && !defined(_POSIX_C_SOURCE) && \ | |
!defined(_XOPEN_SOURCE) && !defined(_NETBSD_SOURCE) | |
#define _NETBSD_SOURCE 1 | |
#endif | |
#if ((_POSIX_C_SOURCE - 0) >= 199506L || (_XOPEN_SOURCE - 0) >= 500) && \ | |
!defined(_REENTRANT) | |
#define _REENTRANT | |
#endif |