From ec7768b68d0efda8f5641973e969bc383f605390 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Sun, 20 Feb 2022 22:03:14 -0800
Subject: [PATCH] futex: fix build on 32-bit architectures using 64-bit time_t

Fix the following build failure on 32-bit architectures using 64-bit
time_t (e.g. riscv32):
| ./boost/fiber/detail/futex.hpp:31:23: error: use of undeclared identifier 'SYS_futex'
|     return ::syscall( SYS_futex, addr, op, x, nullptr, nullptr, 0);
|                       ^
| 1 error generated.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 include/boost/fiber/detail/futex.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/boost/fiber/detail/futex.hpp b/include/boost/fiber/detail/futex.hpp
index e64bd599..d0353e9e 100644
--- a/include/boost/fiber/detail/futex.hpp
+++ b/include/boost/fiber/detail/futex.hpp
@@ -12,6 +12,10 @@
 
 #include <boost/fiber/detail/config.hpp>
 
+#ifndef SYS_futex
+#define SYS_futex SYS_futex_time64
+#endif
+
 #if BOOST_OS_LINUX
 extern "C" {
 #include <linux/futex.h>