2 files changed, 50 insertions, 27 deletions

diff --git a/src/sys/socket.rs b/src/sys/socket.rs
index bef64d7c..5703cbb5 100644
--- a/src/sys/socket.rs
+++ b/src/sys/socket.rs
@@ -215,6 +215,7 @@ pub fn accept(sockfd: Fd) -> SysResult<Fd> {
     Ok(res)
 }
 
+#[cfg(not(any(target_os = "macos", target_os = "ios")))]
 pub fn accept4(sockfd: Fd, flags: SockFlag) -> SysResult<Fd> {
     use libc::sockaddr;
 
@@ -225,35 +226,46 @@ pub fn accept4(sockfd: Fd, flags: SockFlag) -> SysResult<Fd> {
         static accept4: *const ();
     }
 
-    let feat_atomic = !accept4.is_null();
-
-    let res = if feat_atomic {
-        unsafe {
+    if !accept4.is_null() {
+        let res = unsafe {
             mem::transmute::<*const (), F>(accept4)(
                 sockfd, ptr::null_mut(), ptr::null_mut(), flags.bits)
+        };
+
+        if res < 0 {
+            return Err(SysError::last());
         }
+
+        Ok(res)
     } else {
-        unsafe { ffi::accept(sockfd, ptr::null_mut(), ptr::null_mut()) }
-    };
+        accept4_polyfill(sockfd, flags)
+    }
+}
+
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+fn accept4(sockfd: Fd, flags: SockFlag) -> SysResult<Fd> {
+    accept4_polyfill(sockfd, flags)
+}
+
+#[inline]
+fn accept4_polyfill(sockfd: Fd, flags: SockFlag) -> SysResult<Fd> {
+    let res =  unsafe { ffi::accept(sockfd, ptr::null_mut(), ptr::null_mut()) };
 
     if res < 0 {
         return Err(SysError::last());
     }
 
-    if !feat_atomic {
-        if flags.contains(SOCK_CLOEXEC) {
-            try!(fcntl(res, F_SETFD(FD_CLOEXEC)));
-        }
+    if flags.contains(SOCK_CLOEXEC) {
+        try!(fcntl(res, F_SETFD(FD_CLOEXEC)));
+    }
 
-        if flags.contains(SOCK_NONBLOCK) {
-            try!(fcntl(res, F_SETFL(O_NONBLOCK)));
-        }
+    if flags.contains(SOCK_NONBLOCK) {
+        try!(fcntl(res, F_SETFL(O_NONBLOCK)));
     }
 
     Ok(res)
 }
 
-
 pub fn connect(sockfd: Fd, addr: &SockAddr) -> SysResult<()> {
     let res = unsafe {
         match *addr {
diff --git a/src/unistd.rs b/src/unistd.rs
index cef12f0e..0774d260 100644
--- a/src/unistd.rs
+++ b/src/unistd.rs
@@ -95,9 +95,8 @@ pub fn dup2(oldfd: Fd, newfd: Fd) -> SysResult<Fd> {
     Ok(res)
 }
 
+#[cfg(not(any(target_os = "macos", target_os = "ios")))]
 pub fn dup3(oldfd: Fd, newfd: Fd, flags: OFlag) -> SysResult<Fd> {
-    use errno::EINVAL;
-
     type F = unsafe extern "C" fn(c_int, c_int, c_int) -> c_int;
 
     extern {
@@ -117,21 +116,33 @@ pub fn dup3(oldfd: Fd, newfd: Fd, flags: OFlag) -> SysResult<Fd> {
 
         Ok(res)
     } else {
-        if oldfd == newfd {
-            return Err(SysError { kind: EINVAL });
-        }
+        dup3_polyfill(oldfd, newfd, flags)
+    }
+}
 
-        let fd = try!(dup2(oldfd, newfd));
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+pub fn dup3(oldfd: Fd, newfd: Fd, flags: OFlag) -> SysResult<Fd> {
+    dup3_polyfill(oldfd, newfd, flags)
+}
 
-        if flags.contains(O_CLOEXEC) {
-            if let Err(e) = fcntl(fd, F_SETFD(FD_CLOEXEC)) {
-                let _ = close(fd);
-                return Err(e);
-            }
-        }
+#[inline]
+fn dup3_polyfill(oldfd: Fd, newfd: Fd, flags: OFlag) -> SysResult<Fd> {
+    use errno::EINVAL;
 
-        Ok(fd)
+    if oldfd == newfd {
+        return Err(SysError { kind: EINVAL });
     }
+
+    let fd = try!(dup2(oldfd, newfd));
+
+    if flags.contains(O_CLOEXEC) {
+        if let Err(e) = fcntl(fd, F_SETFD(FD_CLOEXEC)) {
+            let _ = close(fd);
+            return Err(e);
+        }
+    }
+
+    Ok(fd)
 }
 
 #[inline]