Index: ChangeLog
===================================================================
RCS file: /cvs/src/src/newlib/ChangeLog,v
retrieving revision 1.1487
diff -p -u -r1.1487 ChangeLog
--- ChangeLog	25 Feb 2010 16:16:15 -0000	1.1487
+++ ChangeLog	25 Feb 2010 17:26:33 -0000
@@ -1,3 +1,10 @@
+2010-02-25  Craig Howland <howland@LGSInnovations.com>
+       
+	* libc/include/sys/config.h:  Add POSIX.1-permitted definition of
+	_POSIX_C_SOURCE if not already defined and _XOPEN_SOURCE has an
+	appropriate value.  (Since config.h gets included everywhere, it is
+	a good spot for this.)  Specifically, check for POSIX.1-2008 value.
+
 2010-02-25  Corinna Vinschen  <corinna@vinschen.de>
 
 	* libc/locale/locale.c (loadlocale): Fix typo in comment.
Index: libc/include/sys/config.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/sys/config.h,v
retrieving revision 1.56
diff -p -u -r1.56 config.h
--- libc/include/sys/config.h	10 Dec 2009 17:12:11 -0000	1.56
+++ libc/include/sys/config.h	25 Feb 2010 17:26:33 -0000
@@ -1,6 +1,19 @@
 #ifndef __SYS_CONFIG_H__
 #define __SYS_CONFIG_H__
 
+/* Per the permission given in POSIX.1-2008 section 2.2.1, define
+ * _POSIX_C_SOURCE if _XOPEN_SOURCE is defined and _POSIX_C_SOURCE is not.
+ * (_XOPEN_SOURCE indicates that XSI extensions are desired by an application.)
+ * This permission is first granted in 2008, but it is used for 2001, anyway.
+ */
+#if !defined(_POSIX_C_SOURCE)  &&  defined(_XOPEN_SOURCE) 
+  #if _XOPEN_SOURCE == 700	/* POSIX.1-2008 */
+    #define _POSIX_C_SOURCE       200809L
+   #elif _XOPEN_SOURCE == 600	/* POSIX.1-2001 */
+    #define _POSIX_C_SOURCE       200112L
+  #endif
+#endif
+
 #include <machine/ieeefp.h>  /* floating point macros */
 
 /* exceptions first */