$OpenBSD: patch-tools_gn_args_cc,v 1.4 2017/10/28 07:36:01 robert Exp $

Index: tools/gn/args.cc
--- tools/gn/args.cc.orig
+++ tools/gn/args.cc
@@ -304,6 +304,8 @@ void Args::SetSystemVarsLocked(Scope* dest) const {
   os = "netbsd";
 #elif defined(OS_AIX)
   os = "aix";
+#elif defined(OS_OPENBSD)
+  os = "openbsd";
 #else
   #error Unknown OS type.
 #endif
