From 267152505b6b41de09a44db0fcbf01b55499853e Mon Sep 17 00:00:00 2001
From: Hin-Tak Leung <htl10@users.sourceforge.net>
Date: Fri, 4 Dec 2020 23:20:13 +0000
Subject: [PATCH] better fix for older compiler than gcc 5

Reference: kernel's include/linux/compiler_attributes.h
---
 sound-compatible-4.18.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound-compatible-4.18.h b/sound-compatible-4.18.h
index c9fe0f6..eefa7de 100644
--- a/sound-compatible-4.18.h
+++ b/sound-compatible-4.18.h
@@ -16,7 +16,11 @@
 #endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(5,4,0)
-#if defined(__has_attribute) && __has_attribute(__fallthrough__)
+#ifndef __has_attribute
+# define __has_attribute(x) __GCC4_has_attribute_##x
+# define __GCC4_has_attribute___fallthrough__         0
+#endif
+#if __has_attribute(__fallthrough__)
 # define fallthrough                    __attribute__((__fallthrough__))
 #else
 # define fallthrough                    do {} while (0)  /* fallthrough */