just define _GNU_SOURCE

libc/misc/fnmatch/fnmatch.c

@@ -25,7 +25,7 @@
 
 /* Enable GNU extensions in fnmatch.h.  */
 #ifndef _GNU_SOURCE
-# define _GNU_SOURCE	1
+# define _GNU_SOURCE
 #endif
 
 #include <features.h>

libc/misc/fnmatch/fnmatch_old.c

@@ -21,7 +21,7 @@ Cambridge, MA 02139, USA.  */
 
 /* Enable GNU extensions in fnmatch.h.  */
 #ifndef _GNU_SOURCE
-# define _GNU_SOURCE	1
+# define _GNU_SOURCE
 #endif
 
 #include <errno.h>

libc/sysdeps/linux/frv/crtreloc.c

@@ -26,7 +26,7 @@ License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */
 
-#define _GNU_SOURCE 1
+#define _GNU_SOURCE
 #include <sys/types.h>
 #include <link.h>