misc Clippy cleanup

* Fix race conditions in the tests.  Two tests were grabbing a mutex but
  immediately dropping it.  Thank you, Clippy.

* Remove vestigial Windows support.  Remove some code added to support
  Windows in 2015.  Nix is no longer intended to ever run on Windows.

* Various other minor Clippy lints.

6 files changed, 37 insertions, 43 deletions

diff --git a/test/sys/test_ioctl.rs b/test/sys/test_ioctl.rs
index fa4510a6..ddb86968 100644
--- a/test/sys/test_ioctl.rs
+++ b/test/sys/test_ioctl.rs
@@ -56,10 +56,10 @@ mod linux {
     #[test]
     fn test_op_write_64() {
         if cfg!(any(target_arch = "mips64", target_arch="powerpc64")){
-            assert_eq!(request_code_write!(b'z', 10, (1 as u64) << 32) as u32,
+            assert_eq!(request_code_write!(b'z', 10, 1u64 << 32) as u32,
                        0x8000_7A0A);
         } else {
-            assert_eq!(request_code_write!(b'z', 10, (1 as u64) << 32) as u32,
+            assert_eq!(request_code_write!(b'z', 10, 1u64 << 32) as u32,
                        0x4000_7A0A);
         }
 
@@ -80,10 +80,10 @@ mod linux {
     #[test]
     fn test_op_read_64() {
         if cfg!(any(target_arch = "mips64", target_arch="powerpc64")){
-            assert_eq!(request_code_read!(b'z', 10, (1 as u64) << 32) as u32,
+            assert_eq!(request_code_read!(b'z', 10, 1u64 << 32) as u32,
                        0x4000_7A0A);
         } else {
-            assert_eq!(request_code_read!(b'z', 10, (1 as u64) << 32) as u32,
+            assert_eq!(request_code_read!(b'z', 10, 1u64 << 32) as u32,
                        0x8000_7A0A);
         }
     }
@@ -97,7 +97,7 @@ mod linux {
     #[cfg(target_pointer_width = "64")]
     #[test]
     fn test_op_read_write_64() {
-        assert_eq!(request_code_readwrite!(b'z', 10, (1 as u64) << 32) as u32,
+        assert_eq!(request_code_readwrite!(b'z', 10, 1u64 << 32) as u32,
                    0xC000_7A0A);
     }
 }
@@ -131,7 +131,7 @@ mod bsd {
     #[cfg(target_pointer_width = "64")]
     #[test]
     fn test_op_write_64() {
-        assert_eq!(request_code_write!(b'z', 10, (1 as u64) << 32), 0x8000_7A0A);
+        assert_eq!(request_code_write!(b'z', 10, 1u64 << 32), 0x8000_7A0A);
     }
 
     #[test]
@@ -143,7 +143,7 @@ mod bsd {
     #[cfg(target_pointer_width = "64")]
     #[test]
     fn test_op_read_64() {
-        assert_eq!(request_code_read!(b'z', 10, (1 as u64) << 32), 0x4000_7A0A);
+        assert_eq!(request_code_read!(b'z', 10, 1u64 << 32), 0x4000_7A0A);
     }
 
     #[test]
@@ -155,7 +155,7 @@ mod bsd {
     #[cfg(target_pointer_width = "64")]
     #[test]
     fn test_op_read_write_64() {
-        assert_eq!(request_code_readwrite!(b'z', 10, (1 as u64) << 32), 0xC000_7A0A);
+        assert_eq!(request_code_readwrite!(b'z', 10, 1u64 << 32), 0xC000_7A0A);
     }
 }
 
diff --git a/test/sys/test_signal.rs b/test/sys/test_signal.rs
index fdb7f36d..c8c13e52 100644
--- a/test/sys/test_signal.rs
+++ b/test/sys/test_signal.rs
@@ -1,4 +1,3 @@
-use libc;
 #[cfg(not(target_os = "redox"))]
 use nix::Error;
 use nix::sys::signal::*;
@@ -53,9 +52,9 @@ fn test_sigprocmask() {
 
     // Make sure the old set doesn't contain the signal, otherwise the following
     // test don't make sense.
-    assert_eq!(old_signal_set.contains(SIGNAL), false,
-               "the {:?} signal is already blocked, please change to a \
-                different one", SIGNAL);
+    assert!(!old_signal_set.contains(SIGNAL),
+            "the {:?} signal is already blocked, please change to a \
+             different one", SIGNAL);
 
     // Now block the signal.
     let mut signal_set = SigSet::empty();
@@ -67,8 +66,8 @@ fn test_sigprocmask() {
     old_signal_set.clear();
     sigprocmask(SigmaskHow::SIG_BLOCK, None, Some(&mut old_signal_set))
         .expect("expect to be able to retrieve old signals");
-    assert_eq!(old_signal_set.contains(SIGNAL), true,
-               "expected the {:?} to be blocked", SIGNAL);
+    assert!(old_signal_set.contains(SIGNAL),
+            "expected the {:?} to be blocked", SIGNAL);
 
     // Reset the signal.
     sigprocmask(SigmaskHow::SIG_UNBLOCK, Some(&signal_set), None)
diff --git a/test/sys/test_socket.rs b/test/sys/test_socket.rs
index 32318ef0..c22eaeb1 100644
--- a/test/sys/test_socket.rs
+++ b/test/sys/test_socket.rs
@@ -7,7 +7,6 @@ use std::path::Path;
 use std::slice;
 use std::str::FromStr;
 use libc::c_char;
-use tempfile;
 #[cfg(any(target_os = "linux", target_os= "android"))]
 use crate::*;
 
@@ -81,7 +80,7 @@ pub fn test_addr_equality_path() {
     let path = "/foo/bar";
     let actual = Path::new(path);
     let addr1 = UnixAddr::new(actual).unwrap();
-    let mut addr2 = addr1.clone();
+    let mut addr2 = addr1;
 
     addr2.0.sun_path[10] = 127;
 
@@ -168,7 +167,7 @@ mod recvfrom {
     use std::thread;
     use super::*;
 
-    const MSG: &'static [u8] = b"Hello, World!";
+    const MSG: &[u8] = b"Hello, World!";
 
     fn sendrecv<Fs, Fr>(rsock: RawFd, ssock: RawFd, f_send: Fs, mut f_recv: Fr) -> Option<SockAddr>
         where
@@ -318,6 +317,7 @@ mod recvfrom {
         target_os = "freebsd",
         target_os = "netbsd",
     ))]
+    #[allow(clippy::vec_init_then_push)]
     #[test]
     pub fn udp_sendmmsg() {
         use nix::sys::uio::IoVec;
@@ -367,7 +367,7 @@ mod recvfrom {
             }
             sendmmsg(s, msgs.iter(), flags)
                 .map(move |sent_bytes| {
-                    assert!(sent_bytes.len() >= 1);
+                    assert!(!sent_bytes.is_empty());
                     for sent in &sent_bytes {
                         assert_eq!(*sent, m.len());
                     }
@@ -425,7 +425,7 @@ mod recvfrom {
 
         for iov in &iovs {
             msgs.push_back(RecvMmsgData {
-                iov: iov,
+                iov,
                 cmsg_buffer: None,
             })
         };
@@ -497,7 +497,7 @@ mod recvfrom {
 
         for iov in &iovs {
             msgs.push_back(RecvMmsgData {
-                iov: iov,
+                iov,
                 cmsg_buffer: None,
             })
         };
@@ -835,12 +835,9 @@ pub fn test_sendmsg_ipv6packetinfo() {
     let inet_addr = InetAddr::from_std(&std_sa);
     let sock_addr = SockAddr::new_inet(inet_addr);
 
-    match bind(sock, &sock_addr) {
-        Err(Error::Sys(Errno::EADDRNOTAVAIL)) => {
-            println!("IPv6 not available, skipping test.");
-            return;
-        },
-        _ => (),
+    if let Err(Error::Sys(Errno::EADDRNOTAVAIL)) = bind(sock, &sock_addr) {
+        println!("IPv6 not available, skipping test.");
+        return;
     }
 
     let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
@@ -1399,8 +1396,8 @@ pub fn test_recvif() {
                 _ => panic!("unexpected additional control msg"),
             }
         }
-        assert_eq!(rx_recvif, true);
-        assert_eq!(rx_recvdstaddr, true);
+        assert!(rx_recvif);
+        assert!(rx_recvdstaddr);
         assert_eq!(msg.bytes, 8);
         assert_eq!(
             iovec[0].as_slice(),
@@ -1479,18 +1476,16 @@ pub fn test_recv_ipv6pktinfo() {
         );
 
         let mut cmsgs = msg.cmsgs();
-        match cmsgs.next() {
-            Some(ControlMessageOwned::Ipv6PacketInfo(pktinfo)) => {
-                let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
-                assert_eq!(
-                    pktinfo.ipi6_ifindex as libc::c_uint,
-                    i,
-                    "unexpected ifindex (expected {}, got {})",
-                    i,
-                    pktinfo.ipi6_ifindex
-                );
-            },
-            _ => (),
+        if let Some(ControlMessageOwned::Ipv6PacketInfo(pktinfo)) = cmsgs.next()
+        {
+            let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
+            assert_eq!(
+                pktinfo.ipi6_ifindex as libc::c_uint,
+                i,
+                "unexpected ifindex (expected {}, got {})",
+                i,
+                pktinfo.ipi6_ifindex
+            );
         }
         assert!(cmsgs.next().is_none(), "unexpected additional control msg");
         assert_eq!(msg.bytes, 8);
diff --git a/test/sys/test_sockopt.rs b/test/sys/test_sockopt.rs
index d151cf55..e0ed0f7c 100644
--- a/test/sys/test_sockopt.rs
+++ b/test/sys/test_sockopt.rs
@@ -74,7 +74,7 @@ fn test_bindtodevice() {
 fn test_so_tcp_keepalive() {
     let fd = socket(AddressFamily::Inet, SockType::Stream, SockFlag::empty(), SockProtocol::Tcp).unwrap();
     setsockopt(fd, sockopt::KeepAlive, &true).unwrap();
-    assert_eq!(getsockopt(fd, sockopt::KeepAlive).unwrap(), true);
+    assert!(getsockopt(fd, sockopt::KeepAlive).unwrap());
 
     #[cfg(any(target_os = "android",
               target_os = "dragonfly",
diff --git a/test/sys/test_uio.rs b/test/sys/test_uio.rs
index aede530a..9dd4f01d 100644
--- a/test/sys/test_uio.rs
+++ b/test/sys/test_uio.rs
@@ -214,7 +214,7 @@ fn test_process_vm_readv() {
     use crate::*;
 
     require_capability!(CAP_SYS_PTRACE);
-    let _ = crate::FORK_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m = crate::FORK_MTX.lock().expect("Mutex got poisoned by another test");
 
     // Pre-allocate memory in the child, since allocation isn't safe
     // post-fork (~= async-signal-safe)
diff --git a/test/sys/test_wait.rs b/test/sys/test_wait.rs
index 5bb298eb..f68b8b08 100644
--- a/test/sys/test_wait.rs
+++ b/test/sys/test_wait.rs
@@ -8,7 +8,7 @@ use libc::_exit;
 #[test]
 #[cfg(not(target_os = "redox"))]
 fn test_wait_signal() {
-    let _ = crate::FORK_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m = crate::FORK_MTX.lock().expect("Mutex got poisoned by another test");
 
     // Safe: The child only calls `pause` and/or `_exit`, which are async-signal-safe.
     match unsafe{fork()}.expect("Error: Fork Failed") {