From 9bd0efee359d5436b3b8433dc76c69315b1126a3 Mon Sep 17 00:00:00 2001
From: Manuel Bentele
Date: Mon, 16 Nov 2020 09:01:54 +0100
Subject: [KERNEL] add support for Linux kernel 4.19 on Ubuntu 18.04 (GCC 7.5)

This patch replaces the __VA_OPT__ varadic macro for the C preprocessor
with a builtin GCC extension for optional varadic arguments. Based on
this change, the dnbd3 Linux kernel module can be also built with GCC
7.5 on a fresh Ubuntu 18.04 with Linux kernel version 4.19.x.
---
 src/kernel/net.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

(limited to 'src/kernel/net.c')

diff --git a/src/kernel/net.c b/src/kernel/net.c
index a044be2..a0444d2 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -55,24 +55,24 @@
  */
 #define __dnbd3_dev_dbg_host(dev, host, fmt, ...) do { \
 	if ((host).type == HOST_IP4) { \
-		dev_dbg(dnbd3_device_to_dev((dev)), "(%pI4:%d): "   fmt, (host).addr, (int)ntohs((host).port) __VA_OPT__(,) __VA_ARGS__); \
+		dev_dbg(dnbd3_device_to_dev((dev)), "(%pI4:%d): "   fmt, (host).addr, (int)ntohs((host).port), ##__VA_ARGS__); \
 	} else { \
-		dev_dbg(dnbd3_device_to_dev((dev)), "([%pI6]:%d): " fmt, (host).addr, (int)ntohs((host).port) __VA_OPT__(,) __VA_ARGS__); \
+		dev_dbg(dnbd3_device_to_dev((dev)), "([%pI6]:%d): " fmt, (host).addr, (int)ntohs((host).port), ##__VA_ARGS__); \
 	} \
 } while (0)
 
 #define __dnbd3_dev_err_host(dev, host, fmt, ...) do { \
 	if ((host).type == HOST_IP4) { \
-		dev_err(dnbd3_device_to_dev((dev)), "(%pI4:%d): "   fmt, (host).addr, (int)ntohs((host).port) __VA_OPT__(,) __VA_ARGS__); \
+		dev_err(dnbd3_device_to_dev((dev)), "(%pI4:%d): "   fmt, (host).addr, (int)ntohs((host).port), ##__VA_ARGS__); \
 	} else { \
-		dev_err(dnbd3_device_to_dev((dev)), "([%pI6]:%d): " fmt, (host).addr, (int)ntohs((host).port) __VA_OPT__(,) __VA_ARGS__); \
+		dev_err(dnbd3_device_to_dev((dev)), "([%pI6]:%d): " fmt, (host).addr, (int)ntohs((host).port), ##__VA_ARGS__); \
 	} \
 } while (0)
 
-#define dnbd3_dev_dbg_host_cur(dev, fmt, ...) __dnbd3_dev_dbg_host((dev), (dev)->cur_server.host,     fmt __VA_OPT__(,) __VA_ARGS__)
-#define dnbd3_dev_err_host_cur(dev, fmt, ...) __dnbd3_dev_err_host((dev), (dev)->cur_server.host,     fmt __VA_OPT__(,) __VA_ARGS__)
-#define dnbd3_dev_dbg_host_alt(dev, fmt, ...) __dnbd3_dev_dbg_host((dev), (dev)->alt_servers[i].host, fmt __VA_OPT__(,) __VA_ARGS__)
-#define dnbd3_dev_err_host_alt(dev, fmt, ...) __dnbd3_dev_err_host((dev), (dev)->alt_servers[i].host, fmt __VA_OPT__(,) __VA_ARGS__)
+#define dnbd3_dev_dbg_host_cur(dev, fmt, ...) __dnbd3_dev_dbg_host((dev), (dev)->cur_server.host,     fmt, ##__VA_ARGS__)
+#define dnbd3_dev_err_host_cur(dev, fmt, ...) __dnbd3_dev_err_host((dev), (dev)->cur_server.host,     fmt, ##__VA_ARGS__)
+#define dnbd3_dev_dbg_host_alt(dev, fmt, ...) __dnbd3_dev_dbg_host((dev), (dev)->alt_servers[i].host, fmt, ##__VA_ARGS__)
+#define dnbd3_dev_err_host_alt(dev, fmt, ...) __dnbd3_dev_err_host((dev), (dev)->alt_servers[i].host, fmt, ##__VA_ARGS__)
 
 static inline dnbd3_server_t *get_free_alt_server(dnbd3_device_t * const dev)
 {
-- 
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