From 81fe55ef317b826a3418a7bc440375469f00a5f0 Mon Sep 17 00:00:00 2001
From: Ti-Yen Yen <thingkingland@icloud.com>
Date: Fri, 9 Oct 2020 13:50:31 -0700
Subject: [PATCH] Build successfully with clang

---
 Makefile         | 3 +++
 src/base/io/io.c | 1 +
 2 files changed, 4 insertions(+)

diff --git a/Makefile b/Makefile
index 583bc25bc6..e8bcd4edd1 100644
--- a/Makefile
+++ b/Makefile
@@ -129,9 +129,12 @@ CFLAGS += -Wno-unused-but-set-variable
 endif
 else
 $(info $(MSG_PREFIX)Found GCC_MAJOR>=5)
+CLANG_HEADER=$(shell $(CC) --version | grep -w clang)
+ifeq (,$(CLANG_HEADER))
 CFLAGS += -Wno-unused-but-set-variable
 endif
 endif
+endif
 
 endif
 
diff --git a/src/base/io/io.c b/src/base/io/io.c
index c2363cb520..d483bbf6ee 100644
--- a/src/base/io/io.c
+++ b/src/base/io/io.c
@@ -18,6 +18,7 @@
 
 ***********************************************************************/
 
+#include <unistd.h>
 #include "ioAbc.h"
 #include "base/main/mainInt.h"
 #include "aig/saig/saig.h"