From 599bab84a1019ccd6228dcc5a8bf8b9a33a96452 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Wed, 20 Dec 2017 10:12:28 +0000
Subject: [PATCH] Condition out AES-NI support if using a too-old clang.

A clang too old to have __attribute__((target)) will not manage to
compile the clang-style hardware-accelerated functions, so it
shouldn't try.
---
 sshaes.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sshaes.c b/sshaes.c
index 7ebeb5be..50879913 100644
--- a/sshaes.c
+++ b/sshaes.c
@@ -1151,6 +1151,14 @@ const struct ssh2_ciphers ssh2_aes = {
 #   undef COMPILER_SUPPORTS_AES_NI
 #endif
 
+#if defined(__clang__)
+#   if !__has_attribute(target)
+/* If clang is old enough not to support __attribute__((target(...)))
+ * as used below, then we can't use this code after all. */
+#      undef COMPILER_SUPPORTS_AES_NI
+#   endif
+#endif
+
 #ifdef COMPILER_SUPPORTS_AES_NI
 
 /*