From 1b9cff1c5d09adb0af858992e2a2df01b1d4dc58 Mon Sep 17 00:00:00 2001
From: John Safranek <john@wolfssl.com>
Date: Wed, 16 May 2018 09:55:16 -0400
Subject: [PATCH] Hush ar warning At some point, ar on Ubuntu started throwing
 the following warning:

    ar: `u' modifier ignored since `D' is the default (see `U')

Add the "U" option to the ar flags if the version of ar supports it.
(The version used by macOS does not support the flag, for example.) The
AR_FLAGS set in configure will later be used by libtool.
---
 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index c96e5ce2a..0f8a47530 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,6 +16,10 @@ AC_CONFIG_AUX_DIR([build-aux])
 : ${CFLAGS=""}
 : ${CXXFLAGS=""}
 
+# Test ar for the "U" option. Should be checked before the libtool macros.
+xxx_ar_flags=$((ar --help) 2>&1)
+AS_CASE([$xxx_ar_flags],[*'use actual timestamps and uids/gids'*],[: ${AR_FLAGS="Ucru"}])
+
 AC_CANONICAL_HOST
 AC_CANONICAL_BUILD