minix/nbsd_include/sys/featuretest.h
2011-02-21 13:13:55 +00:00

81 lines
2.9 KiB
C

/* $NetBSD: featuretest.h,v 1.9 2009/05/04 16:44:14 ginsbach 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
* _POSIX_C_SOURCE == 200809L IEEE Std 1003.1-2008
*
* 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
* _XOPEN_SOURCE == 700 IEEE Std 1003.1-2008, 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
/* Never define _REENTRANT on Minix */
#ifdef __minix
#if ((_POSIX_C_SOURCE - 0) >= 199506L || (_XOPEN_SOURCE - 0) >= 500) && \
!defined(_REENTRANT)
#define _REENTRANT
#endif
#endif /* __minix */