Define OS_LINUX only if it's not defined yet

diff --git a/src/utilities.h b/src/utilities.h
index 5f79968..101ca64 100644 (file)
--- a/src/utilities.h
+++ b/src/utilities.h
@@ -39,7 +39,9 @@
 #elif defined(__CYGWIN__) || defined(__CYGWIN32__)
 # define OS_CYGWIN
 #elif defined(linux) || defined(__linux) || defined(__linux__)
-# define OS_LINUX
+# ifndef OS_LINUX
+#  define OS_LINUX
+# endif
 #elif defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
 # define OS_MACOSX
 #elif defined(__FreeBSD__)