From e436e40b57125472ba732a5d39407ff52f008f52 Mon Sep 17 00:00:00 2001
From: "Yann E. MORIN" <yann.morin.1998@free.fr>
Date: Thu, 25 Dec 2014 18:52:00 +0100
Subject: [PATCH] configure: add check for bswap_64

include/f2fs_fs.h checks the HAVE_BSWAP_64 conidtional, but configure
nevers checks for it.

Add a check that the function is indeed declared, and fix the variable
name to match the naming scheme of autoconf (and not those of WAF like
is used by samba), and adapt the check as suggested in the autoconf
manual.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Gustavo Zacarias <gustavo@zacarias.com.ar>
---
 configure.ac      | 3 +++
 include/f2fs_fs.h | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 7cfd9b4..ae451b8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -72,6 +72,9 @@ AC_CHECK_FUNCS_ONCE([
 	memset
 ])
 
+AS_IF([test "$ac_cv_header_byteswap_h" = "yes"],
+      [AC_CHECK_DECLS([bswap_64],,,[#include <byteswap.h>])])
+
 # Install directories
 AC_PREFIX_DEFAULT([/usr])
 AC_SUBST([sbindir], [/sbin])
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index 0c3ba04..4dc2426 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -63,7 +63,7 @@ static inline uint32_t bswap_32(uint32_t val)
 }
 #endif /* !HAVE_BYTESWAP_H */
 
-#if !HAVE_BSWAP_64
+#if defined HAVE_DECL_BSWAP_64 && !HAVE_DECL_BSWAP_64
 /**
  * bswap_64 - reverse bytes in a uint64_t value.
  * @val: value whose bytes to swap.
-- 
1.9.1