Fix build on musl targets.

Author: kinetiknz

src/sys/socket/mod.rs

@@ -418,10 +418,12 @@ impl<'a> ControlMessage<'a> {
     unsafe fn encode_into<'b>(&self, buf: &mut &'b mut [u8]) {
         match *self {
             ControlMessage::ScmRights(fds) => {
-                let cmsg = cmsghdr {
-                    cmsg_len: self.len() as _,
-                    cmsg_level: libc::SOL_SOCKET,
-                    cmsg_type: libc::SCM_RIGHTS,
+                let cmsg = {
+                  let mut cmsg: cmsghdr = mem::uninitialized();
+                  cmsg.cmsg_len = self.len() as _;
+                  cmsg.cmsg_level = libc::SOL_SOCKET;
+                  cmsg.cmsg_type = libc::SCM_RIGHTS;
+                  cmsg
                 };
                 copy_bytes(&cmsg, buf);
 
@@ -436,10 +438,12 @@ impl<'a> ControlMessage<'a> {
                 copy_bytes(fds, buf);
             },
             ControlMessage::ScmTimestamp(t) => {
-                let cmsg = cmsghdr {
-                    cmsg_len: self.len() as _,
-                    cmsg_level: libc::SOL_SOCKET,
-                    cmsg_type: libc::SCM_TIMESTAMP,
+                let cmsg = {
+                  let mut cmsg: cmsghdr = mem::uninitialized();
+                  cmsg.cmsg_len = self.len() as _;
+                  cmsg.cmsg_level = libc::SOL_SOCKET;
+                  cmsg.cmsg_type = libc::SCM_TIMESTAMP;
+                  cmsg
                 };
                 copy_bytes(&cmsg, buf);
 
@@ -499,14 +503,16 @@ pub fn sendmsg<'a>(fd: RawFd, iov: &[IoVec<&'a [u8]>], cmsgs: &[ControlMessage<'
         ptr::null()
     };
 
-    let mhdr = msghdr {
-        msg_name: name as *mut _,
-        msg_namelen: namelen,
-        msg_iov: iov.as_ptr() as *mut _,
-        msg_iovlen: iov.len() as _,
-        msg_control: cmsg_ptr as *mut _,
-        msg_controllen: capacity as _,
-        msg_flags: 0,
+    let mhdr = unsafe {
+        let mut mhdr: msghdr = mem::uninitialized();
+        mhdr.msg_name = name as *mut _;
+        mhdr.msg_namelen = namelen;
+        mhdr.msg_iov = iov.as_ptr() as *mut _;
+        mhdr.msg_iovlen = iov.len() as _;
+        mhdr.msg_control = cmsg_ptr as *mut _;
+        mhdr.msg_controllen = capacity as _;
+        mhdr.msg_flags = 0;
+        mhdr
     };
     let ret = unsafe { libc::sendmsg(fd, &mhdr, flags.bits()) };
 
@@ -522,14 +528,16 @@ pub fn recvmsg<'a, T>(fd: RawFd, iov: &[IoVec<&mut [u8]>], cmsg_buffer: Option<&
         Some(cmsg_buffer) => (cmsg_buffer as *mut _, mem::size_of_val(cmsg_buffer)),
         None => (0 as *mut _, 0),
     };
-    let mut mhdr = msghdr {
-        msg_name: &mut address as *mut _ as *mut _,
-        msg_namelen: mem::size_of::<sockaddr_storage>() as socklen_t,
-        msg_iov: iov.as_ptr() as *mut _,
-        msg_iovlen: iov.len() as _,
-        msg_control: msg_control as *mut _,
-        msg_controllen: msg_controllen as _,
-        msg_flags: 0,
+    let mut mhdr = unsafe {
+        let mut mhdr: msghdr = mem::uninitialized();
+        mhdr.msg_name = &mut address as *mut _ as *mut _;
+        mhdr.msg_namelen = mem::size_of::<sockaddr_storage>() as socklen_t;
+        mhdr.msg_iov = iov.as_ptr() as *mut _;
+        mhdr.msg_iovlen = iov.len() as _;
+        mhdr.msg_control = msg_control as *mut _;
+        mhdr.msg_controllen = msg_controllen as _;
+        mhdr.msg_flags = 0;
+        mhdr
     };
     let ret = unsafe { libc::recvmsg(fd, &mut mhdr, flags.bits()) };