From d1840ef2ab511bc7edf1267789662fde13a91360 Mon Sep 17 00:00:00 2001
From: Christian Hofstaedtler <christian.hofstaedtler@deduktiva.com>
Date: Sun, 11 Oct 2015 12:59:32 +0200
Subject: [PATCH] Allow use of --enable-asan under clang

Apply the industry standard solution, as clang with
-fsanitize=address apparently enables _FORTIFY_SOURCE, leading
to a redefinition.
---
 m4/pdns_d_fortify_source.m4 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/m4/pdns_d_fortify_source.m4 b/m4/pdns_d_fortify_source.m4
index 605990c47..68e9be5ef 100644
--- a/m4/pdns_d_fortify_source.m4
+++ b/m4/pdns_d_fortify_source.m4
@@ -22,7 +22,7 @@ AC_DEFUN([AC_CC_D_FORTIFY_SOURCE],[
       OLD_CXXFLAGS="$CXXFLAGS"
       CXXFLAGS="-Wall -W -Werror $CXXFLAGS"
       gl_COMPILER_OPTION_IF([-D_FORTIFY_SOURCE=2], [
-        CFLAGS="-D_FORTIFY_SOURCE=2 $CFLAGS"
-        CXXFLAGS="-D_FORTIFY_SOURCE=2 $OLD_CXXFLAGS"
+        CFLAGS="-U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $CFLAGS"
+        CXXFLAGS="-U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $OLD_CXXFLAGS"
       ], [CXXFLAGS="$OLD_CXXFLAGS"], [AC_LANG_PROGRAM([[#include <stdio.h>]],[])])
 ]) 
-- 
2.40.0