From f812a36cee5727147bc897d34ab9af068dd4561e Mon Sep 17 00:00:00 2001
From: Damien Miller <djm@mindrot.org>
Date: Sat, 17 Oct 2020 12:03:34 +1100
Subject: [PATCH] check for and require a C99 capable compiler

recent logging changes use __VA_ARGS__.
---
 configure.ac | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/configure.ac b/configure.ac
index 7005a503e..05f7b713b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -22,6 +22,12 @@ AC_CONFIG_HEADER([config.h])
 AC_PROG_CC([cc gcc])
 AC_CANONICAL_HOST
 AC_C_BIGENDIAN
+AC_PROG_CC_C99
+
+# XXX relax this after reimplementing logit() etc.
+if test "x$ac_cv_prog_cc_c99" = "xno" ; then
+	AC_MSG_ERROR([*** OpenSSH requires a C99 capable compiler ***])
+fi
 
 # Checks for programs.
 AC_PROG_AWK