[Qemu-devel] [PATCH V2 1/3] Darwin: Fix incorrect check for fdatasync() in configure

[Alexandre Raymond <cerbere@gmail.com>]

Under darwin (OS X 10.6.7), a symbol exists for the fdatasync() method
but it is not supported because _POSIX_SYNCHRONIZED_IO is set to '-1'.

Enable fdatasync() only if _POSIX_SYNCHRONIZED_IO is '>0', as per
The Open Group Base Specifications Issue 7.

Signed-off-by: Alexandre Raymond <cerbere@gmail.com>
---
 configure |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/configure b/configure
index a318d37..b21ef75 100755
--- a/configure
+++ b/configure
@@ -2477,7 +2477,13 @@ fi
 fdatasync=no
 cat > $TMPC << EOF
 #include <unistd.h>
-int main(void) { return fdatasync(0); }
+int main(void) {
+#if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
+return fdatasync(0);
+#else
+#abort Not supported
+#endif
+}
 EOF
 if compile_prog "" "" ; then
     fdatasync=yes
-- 
1.7.5