Define our desires for POSIX and X/OPEN API features properly.

Based on a post on the gcc-help mailing list and some subsequent reading,
we can increase our portability to various platforms by directly defining
the POSIX and X/OPEN API feature sets we wish to have available. This patch
does that, and also includes a double-check to ensure that the system
we are compiling on can actually provide the requested feature sets.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@212463 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk.h

@@ -20,6 +20,18 @@
 
 #include "asterisk/autoconfig.h"
 
+#define _POSIX_C_SOURCE 200112L
+#define _XOPEN_SOURCE 600
+
+#include <unistd.h>
+
+#if _POSIX_VERSION < 200112L
+#error System does not support POSIX version 200112.
+#endif
+#if _XOPEN_VERSION < 600
+#error System does not support XOPEN version 600.
+#endif
+
 #if !defined(NO_MALLOC_DEBUG) && !defined(STANDALONE) && defined(MALLOC_DEBUG)
 #include "asterisk/astmm.h"
 #endif
@@ -49,7 +61,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
-#include <unistd.h>
 #include <fcntl.h>
 
 #define	open(a,...)	__ast_fdleak_open(__FILE__,__LINE__,__PRETTY_FUNCTION__, a, __VA_ARGS__)

main/xml.c

@@ -27,9 +27,6 @@
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #if defined(HAVE_LIBXML2)
-#ifndef _POSIX_C_SOURCE	/* Needed on Mac OS X */
-#define _POSIX_C_SOURCE 200112L
-#endif
 #include <libxml/parser.h>
 #include <libxml/tree.h>
 #include <libxml/xinclude.h>