Revised CFLAGS in autogen.sh

autogen.sh

@@ -9,6 +9,11 @@ aclocal -I m4 --force || exit 1
 autoheader --force || exit 1
 automake --add-missing --copy --force || exit 1
 autoconf --force || exit 1
-export CFLAGS="-Wall -g -O0 -Wl,--no-undefined"
-export CXXFLAGS="$CFLAGS"
-./configure "$@" || exit 1
+
+if `echo "$@" | grep -q CFLAGS > /dev/null` ; then
+    ./configure "$@" || exit 1
+else
+    CFLAGS=${CFLAGS-"-Wall -Werror -Wformat -Werror=format-security"}
+    CXXFLAGS="$CFLAGS"
+    ./configure "$@" CFLAGS="$CFLAGS" CXXFLAGS="$CXXFLAGS" || exit 1
+fi