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Diffstat (limited to 'StdLib/Include/sys/featuretest.h')
| -rw-r--r-- | StdLib/Include/sys/featuretest.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/StdLib/Include/sys/featuretest.h b/StdLib/Include/sys/featuretest.h new file mode 100644 index 0000000000..f36396af17 --- /dev/null +++ b/StdLib/Include/sys/featuretest.h @@ -0,0 +1,73 @@ +/* $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
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