From 4c311ffb1f6a1f03eeca0fdb2426ef94eb4cfc29 Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@revosec.ch>
Date: Wed, 4 Jul 2012 14:53:21 +0200
Subject: [PATCH] Check if config.h passed correctly via gcc -include

---
 configure.in                | 1 +
 src/libstrongswan/library.h | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/configure.in b/configure.in
index 51ce46bc2..fc96929f5 100644
--- a/configure.in
+++ b/configure.in
@@ -20,6 +20,7 @@ AC_INIT(strongSwan,5.0.0)
 AM_INIT_AUTOMAKE(tar-ustar)
 AC_CONFIG_MACRO_DIR([m4/config])
 AC_CONFIG_HEADERS([config.h])
+AC_DEFINE([CONFIG_H_INCLUDED], [], [defined if config.h included])
 PKG_PROG_PKG_CONFIG
 
 dnl =================================
diff --git a/src/libstrongswan/library.h b/src/libstrongswan/library.h
index 7e76e1927..d357ddf5a 100644
--- a/src/libstrongswan/library.h
+++ b/src/libstrongswan/library.h
@@ -67,6 +67,10 @@
 #ifndef LIBRARY_H_
 #define LIBRARY_H_
 
+#ifndef CONFIG_H_INCLUDED
+# error config.h not included, pass "-include [...]/config.h" to gcc
+#endif
+
 #include "printf_hook.h"
 #include "utils.h"
 #include "chunk.h"