AX_CHECK_COMPILE_FLAG([-DFORTIFY_SOURCE=2], [CPPFLAGS="$CPPFLAGS -DFORITFY_SOURCE=2"])
AX_CHECK_COMPILE_FLAG([-fwrapv], [CPPFLAGS="$CPPFLAGS -fwrapv"],
[AX_CHECK_COMPILE_FLAG([-fno-strict-overflow], [CPPFLAGS="$CPPFLAGS -fno-strict-overflow"])]
AX_CHECK_COMPILE_FLAG([-DFORTIFY_SOURCE=2], [CPPFLAGS="$CPPFLAGS -DFORITFY_SOURCE=2"])
AX_CHECK_COMPILE_FLAG([-fwrapv], [CPPFLAGS="$CPPFLAGS -fwrapv"],
[AX_CHECK_COMPILE_FLAG([-fno-strict-overflow], [CPPFLAGS="$CPPFLAGS -fno-strict-overflow"])]