syscall: add Utimes on Darwin/FreeBSD, add Futimes everywhere

Needed for CL 1103041 and beyond.

R=adg, bradfitzpatrick
CC=bradfitz, golang-dev
http://codereview.appspot.com/1172042

1 files changed, 8 insertions, 2 deletions

diff --git a/src/pkg/syscall/syscall_linux.go b/src/pkg/syscall/syscall_linux.go
index f98b4cb7a..39ab10309 100644
--- a/src/pkg/syscall/syscall_linux.go
+++ b/src/pkg/syscall/syscall_linux.go
@@ -49,12 +49,18 @@ func Utimes(path string, tv []Timeval) (errno int) {
 	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
 }
 
-//sys	futimesat(dirfd int, path string, times *[2]Timeval) (errno int)
+//sys	futimesat(dirfd int, path *byte, times *[2]Timeval) (errno int)
 func Futimesat(dirfd int, path string, tv []Timeval) (errno int) {
 	if len(tv) != 2 {
 		return EINVAL
 	}
-	return futimesat(dirfd, path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+	return futimesat(dirfd, StringBytePtr(path), (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+func Futimes(fd int, tv []Timeval) (errno int) {
+	// Believe it or not, this is the best we can do on Linux
+	// (and is what glibc does).
+	return Utimes("/proc/self/fd/"+str(fd), tv)
 }
 
 const ImplementsGetwd = true