misc: only define _GNU_SOURCE if not defined

C++ compilers on Linux (g++, clang++) appear to always define this.

diff --git a/src/suricata-common.h b/src/suricata-common.h
index b018c001e383d6c385835ab76eead1876ffaf2bd..b134586328dfb7c92bfce5ed0e0b455f3536e468 100644 (file)
--- a/src/suricata-common.h
+++ b/src/suricata-common.h
@@ -30,7 +30,10 @@
 #define DBG_PERF
 #endif
 
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
+
 #define __USE_GNU
 
 #if defined(__clang_analyzer__)