| Vishal Bhoj | 82c8071 | 2015-12-15 21:13:33 +0530 | [diff] [blame] | 1 | /* $NetBSD: featuretest.h,v 1.8 2005/12/11 12:25:20 christos Exp $ */
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| 2 |
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| 3 | /*
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| 4 | * Written by Klaus Klein <kleink@NetBSD.org>, February 2, 1998.
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| 5 | * Public domain.
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| 6 | *
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| 7 | * NOTE: Do not protect this header against multiple inclusion. Doing
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| 8 | * so can have subtle side-effects due to header file inclusion order
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| 9 | * and testing of e.g. _POSIX_SOURCE vs. _POSIX_C_SOURCE. Instead,
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| 10 | * protect each CPP macro that we want to supply.
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| 11 | */
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| 12 |
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| 13 | /*
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| 14 | * Feature-test macros are defined by several standards, and allow an
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| 15 | * application to specify what symbols they want the system headers to
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| 16 | * expose, and hence what standard they want them to conform to.
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| 17 | * There are two classes of feature-test macros. The first class
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| 18 | * specify complete standards, and if one of these is defined, header
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| 19 | * files will try to conform to the relevant standard. They are:
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| 20 | *
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| 21 | * ANSI macros:
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| 22 | * _ANSI_SOURCE ANSI C89
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| 23 | *
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| 24 | * POSIX macros:
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| 25 | * _POSIX_SOURCE == 1 IEEE Std 1003.1 (version?)
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| 26 | * _POSIX_C_SOURCE == 1 IEEE Std 1003.1-1990
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| 27 | * _POSIX_C_SOURCE == 2 IEEE Std 1003.2-1992
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| 28 | * _POSIX_C_SOURCE == 199309L IEEE Std 1003.1b-1993
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| 29 | * _POSIX_C_SOURCE == 199506L ISO/IEC 9945-1:1996
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| 30 | * _POSIX_C_SOURCE == 200112L IEEE Std 1003.1-2001
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| 31 | *
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| 32 | * X/Open macros:
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| 33 | * _XOPEN_SOURCE System Interfaces and Headers, Issue 4, Ver 2
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| 34 | * _XOPEN_SOURCE_EXTENDED == 1 XSH4.2 UNIX extensions
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| 35 | * _XOPEN_SOURCE == 500 System Interfaces and Headers, Issue 5
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| 36 | * _XOPEN_SOURCE == 520 Networking Services (XNS), Issue 5.2
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| 37 | * _XOPEN_SOURCE == 600 IEEE Std 1003.1-2001, XSI option
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| 38 | *
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| 39 | * NetBSD macros:
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| 40 | * _NETBSD_SOURCE == 1 Make all NetBSD features available.
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| 41 | *
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| 42 | * If more than one of these "major" feature-test macros is defined,
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| 43 | * then the set of facilities provided (and namespace used) is the
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| 44 | * union of that specified by the relevant standards, and in case of
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| 45 | * conflict, the earlier standard in the above list has precedence (so
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| 46 | * if both _POSIX_C_SOURCE and _NETBSD_SOURCE are defined, the version
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| 47 | * of rename() that's used is the POSIX one). If none of the "major"
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| 48 | * feature-test macros is defined, _NETBSD_SOURCE is assumed.
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| 49 | *
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| 50 | * There are also "minor" feature-test macros, which enable extra
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| 51 | * functionality in addition to some base standard. They should be
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| 52 | * defined along with one of the "major" macros. The "minor" macros
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| 53 | * are:
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| 54 | *
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| 55 | * _REENTRANT
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| 56 | * _ISOC99_SOURCE
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| 57 | * _LARGEFILE_SOURCE Large File Support
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| 58 | * <http://ftp.sas.com/standards/large.file/x_open.20Mar96.html>
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| 59 | */
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| 60 |
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| 61 | #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
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| 62 | #define _POSIX_C_SOURCE 1L
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| 63 | #endif
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| 64 |
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| 65 | #if !defined(_ANSI_SOURCE) && !defined(_POSIX_C_SOURCE) && \
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| 66 | !defined(_XOPEN_SOURCE) && !defined(_NETBSD_SOURCE)
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| 67 | #define _NETBSD_SOURCE 1
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| 68 | #endif
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| 69 |
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| 70 | #if ((_POSIX_C_SOURCE - 0) >= 199506L || (_XOPEN_SOURCE - 0) >= 500) && \
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| 71 | !defined(_REENTRANT)
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| 72 | #define _REENTRANT
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| 73 | #endif
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