From cb3ad659f0e5c909b7df5c9cbe84ff429754c669 Mon Sep 17 00:00:00 2001
From: Jason Evans <jasone@canonware.com>
Date: Thu, 3 Nov 2016 21:57:17 -0700
Subject: [PATCH] Use -std=gnu11 if available.

This supersedes -std=gnu99, and enables C11 atomics.
---
 configure.ac | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 3a4f1505..104fd994 100644
--- a/configure.ac
+++ b/configure.ac
@@ -171,9 +171,15 @@ fi
 if test "x$CFLAGS" = "x" ; then
   no_CFLAGS="yes"
   if test "x$GCC" = "xyes" ; then
-    JE_CFLAGS_APPEND([-std=gnu99])
-    if test "x$je_cv_cflags_appended" = "x-std=gnu99" ; then
+dnl    JE_CFLAGS_APPEND([-std=gnu99])
+    JE_CFLAGS_APPEND([-std=gnu11])
+    if test "x$je_cv_cflags_appended" = "x-std=gnu11" ; then
       AC_DEFINE_UNQUOTED([JEMALLOC_HAS_RESTRICT])
+    else
+      JE_CFLAGS_APPEND([-std=gnu99])
+      if test "x$je_cv_cflags_appended" = "x-std=gnu99" ; then
+        AC_DEFINE_UNQUOTED([JEMALLOC_HAS_RESTRICT])
+      fi
     fi
     JE_CFLAGS_APPEND([-Wall])
     JE_CFLAGS_APPEND([-Werror=declaration-after-statement])