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authorJoseph Myers <joseph@codesourcery.com>2013-12-19 13:32:42 +0000
committerJoseph Myers <joseph@codesourcery.com>2013-12-19 13:32:42 +0000
commitc688b4196014e0162a1ff11120f6c9516be0c6cb (patch)
treecbd05e278192c66c63f6d79b26bb0c1e19d805d4 /include/features.h
parent9f6e964c3a951b6e19ed934aec1f0c101c295987 (diff)
downloadglibc-c688b4196014e0162a1ff11120f6c9516be0c6cb.tar.gz
Add _DEFAULT_SOURCE feature test macro.
This patch adds a feature test macro _DEFAULT_SOURCE to enable the default set of header declarations. The intention is: if _DEFAULT_SOURCE is not used there is no change to the set of __USE_* macros glibc defines; if it's used on its own, and without compiler options such as -std=c99 that define __STRICT_ANSI__, again, there is no change; if it's used together with the macros it approximately (i.e., apart from __USE_POSIX_IMPLICITLY) implies (-D_BSD_SOURCE -D_SVID_SOURCE -D_POSIX_C_SOURCE=200809L), again, there is no change. Otherwise, it causes the relevant features to be enabled, even if __STRICT_ANSI__, or another feature test macro, would cause them to be disabled. This macro deliberately bundles the POSIX.1-2008 (non-X/Open) functionality with the BSD/SVID/"misc" functionality, rather than defining a macro that gives just the latter, as many of the header cleanups resulting from removing _BSD_SOURCE and _SVID_SOURCE support are only possible when BSD/SVID/"misc" is always bundled with POSIX.1-2008. Tested x86_64. * include/features.h: Update comment documenting feature test macros. Mention _DEFAULT_SOURCE in comment. [_GNU_SOURCE] (_DEFAULT_SOURCE): Undefine and redefine. [_DEFAULT_SOURCE]: Undefine and redefine _DEFAULT_SOURCE, _BSD_SOURCE and _SVID_SOURCE. [!__STRICT_ANSI__ && !_ISOC99_SOURCE && !_POSIX_SOURCE && !_POSIX_C_SOURCE && !_XOPEN_SOURCE && !_BSD_SOURCE && !_SVID_SOURCE]: Likewise. [_DEFAULT_SOURCE && !_POSIX_SOURCE && !_POSIX_C_SOURCE] (__USE_POSIX_IMPLICITLY): Define. [_DEFAULT_SOURCE && !_POSIX_SOURCE && !_POSIX_C_SOURCE] (_POSIX_SOURCE): Undefine and redefine. [_DEFAULT_SOURCE && !_POSIX_SOURCE && !_POSIX_C_SOURCE] (_POSIX_C_SOURCE): Likewise. * manual/creature.texi (_DEFAULT_SOURCE): Document. (Feature Test Macros): Update documentation of default features.
Diffstat (limited to 'include/features.h')
-rw-r--r--include/features.h49
1 files changed, 36 insertions, 13 deletions
diff --git a/include/features.h b/include/features.h
index cff8bfcf8e..6acd5c899d 100644
--- a/include/features.h
+++ b/include/features.h
@@ -41,17 +41,21 @@
_SVID_SOURCE ISO C, POSIX, and SVID things.
_ATFILE_SOURCE Additional *at interfaces.
_GNU_SOURCE All of the above, plus GNU extensions.
+ _DEFAULT_SOURCE The default set of features (taking precedence over
+ __STRICT_ANSI__).
_REENTRANT Select additionally reentrant object.
_THREAD_SAFE Same as _REENTRANT, often used by other systems.
_FORTIFY_SOURCE If set to numeric value > 0 additional security
measures are defined, according to level.
- The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
- If none of these are defined, the default is to have _SVID_SOURCE,
- _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
- 200112L. If more than one of these are defined, they accumulate.
- For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
- together give you ISO C, 1003.1, and 1003.2, but nothing else.
+ The `-ansi' switch to the GNU C compiler, and standards conformance
+ options such as `-std=c99', define __STRICT_ANSI__. If none of
+ these are defined, or if _DEFAULT_SOURCE is defined, the default is
+ to have _SVID_SOURCE, _BSD_SOURCE, and _POSIX_SOURCE set to one and
+ _POSIX_C_SOURCE set to 200809L. If more than one of these are
+ defined, they accumulate. For example __STRICT_ANSI__,
+ _POSIX_SOURCE and _POSIX_C_SOURCE together give you ISO C, 1003.1,
+ and 1003.2, but nothing else.
These are defined by this file and are used by the
header files to decide what to declare or define:
@@ -160,6 +164,8 @@
# define _XOPEN_SOURCE_EXTENDED 1
# undef _LARGEFILE64_SOURCE
# define _LARGEFILE64_SOURCE 1
+# undef _DEFAULT_SOURCE
+# define _DEFAULT_SOURCE 1
# undef _BSD_SOURCE
# define _BSD_SOURCE 1
# undef _SVID_SOURCE
@@ -168,12 +174,19 @@
# define _ATFILE_SOURCE 1
#endif
-/* If nothing (other than _GNU_SOURCE) is defined,
- define _BSD_SOURCE and _SVID_SOURCE. */
-#if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
- !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
- !defined _XOPEN_SOURCE && !defined _BSD_SOURCE && !defined _SVID_SOURCE)
+/* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined,
+ define _DEFAULT_SOURCE, _BSD_SOURCE and _SVID_SOURCE. */
+#if (defined _DEFAULT_SOURCE \
+ || (!defined __STRICT_ANSI__ \
+ && !defined _ISOC99_SOURCE \
+ && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \
+ && !defined _XOPEN_SOURCE \
+ && !defined _BSD_SOURCE && !defined _SVID_SOURCE))
+# undef _DEFAULT_SOURCE
+# define _DEFAULT_SOURCE 1
+# undef _BSD_SOURCE
# define _BSD_SOURCE 1
+# undef _SVID_SOURCE
# define _SVID_SOURCE 1
#endif
@@ -204,8 +217,18 @@
# define __USE_ISOCXX11 1
#endif
-/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
- (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
+/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
+ is defined, use POSIX.1-2008 (or another version depending on
+ _XOPEN_SOURCE). */
+#ifdef _DEFAULT_SOURCE
+# if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE
+# define __USE_POSIX_IMPLICITLY 1
+# endif
+# undef _POSIX_SOURCE
+# define _POSIX_SOURCE 1
+# undef _POSIX_C_SOURCE
+# define _POSIX_C_SOURCE 200809L
+#endif
#if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
!defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
# define _POSIX_SOURCE 1