Rollup merge of #130962 - nyurik:opts-libs, r=cuviper

Migrate lib's `&Option<T>` into `Option<&T>`

Trying out my new lint rust-lang/rust-clippy#13336 - according to the [video](https://www.youtube.com/watch?v=6c7pZYP_iIE), this could lead to some performance and memory optimizations.

Basic thoughts expressed in the video that seem to make sense:
* `&Option<T>` in an API breaks encapsulation:
  * caller must own T and move it into an Option to call with it
  * if returned, the owner must store it as Option<T> internally in order to return it
* Performance is subject to compiler optimization, but at the basics, `&Option<T>` points to memory that has `presence` flag + value, whereas `Option<&T>` by specification is always optimized to a single pointer.

library/std/src/sys/pal/sgx/net.rs

@@ -78,9 +78,8 @@ fn io_err_to_addr(result: io::Result<&SocketAddr>) -> io::Result<String> {
     }
 }
 
-fn addr_to_sockaddr(addr: &Option<String>) -> io::Result<SocketAddr> {
-    addr.as_ref()
-        .ok_or(io::ErrorKind::AddrNotAvailable)?
+fn addr_to_sockaddr(addr: Option<&str>) -> io::Result<SocketAddr> {
+    addr.ok_or(io::ErrorKind::AddrNotAvailable)?
         .to_socket_addrs()
         // unwrap OK: if an iterator is returned, we're guaranteed to get exactly one entry
         .map(|mut it| it.next().unwrap())
@@ -161,11 +160,11 @@ impl TcpStream {
     }
 
     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
-        addr_to_sockaddr(&self.peer_addr)
+        addr_to_sockaddr(self.peer_addr.as_deref())
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        addr_to_sockaddr(&self.inner.local_addr)
+        addr_to_sockaddr(self.inner.local_addr.as_deref())
     }
 
     pub fn shutdown(&self, _: Shutdown) -> io::Result<()> {
@@ -255,13 +254,14 @@ impl TcpListener {
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        addr_to_sockaddr(&self.inner.local_addr)
+        addr_to_sockaddr(self.inner.local_addr.as_deref())
     }
 
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
         let (fd, local_addr, peer_addr) = usercalls::accept_stream(self.inner.inner.raw())?;
         let peer_addr = Some(peer_addr);
-        let ret_peer = addr_to_sockaddr(&peer_addr).unwrap_or_else(|_| ([0; 4], 0).into());
+        let ret_peer =
+            addr_to_sockaddr(peer_addr.as_deref()).unwrap_or_else(|_| ([0; 4], 0).into());
         Ok((TcpStream { inner: Socket::new(fd, local_addr), peer_addr }, ret_peer))
     }
 

library/std/src/sys/pal/unix/process/process_common.rs

@@ -312,8 +312,8 @@ impl Command {
     }
 
     #[allow(dead_code)]
-    pub fn get_cwd(&self) -> &Option<CString> {
-        &self.cwd
+    pub fn get_cwd(&self) -> Option<&CStr> {
+        self.cwd.as_deref()
     }
     #[allow(dead_code)]
     pub fn get_uid(&self) -> Option<uid_t> {

library/std/src/sys/pal/unix/process/process_unix.rs

@@ -335,7 +335,7 @@ impl Command {
                 cvt(libc::setuid(u as uid_t))?;
             }
         }
-        if let Some(ref cwd) = *self.get_cwd() {
+        if let Some(cwd) = self.get_cwd() {
             cvt(libc::chdir(cwd.as_ptr()))?;
         }
 

library/std/src/sys/pal/unix/process/process_vxworks.rs

@@ -57,7 +57,7 @@ impl Command {
                 t!(cvt_r(|| libc::dup2(fd, libc::STDERR_FILENO)));
             }
 
-            if let Some(ref cwd) = *self.get_cwd() {
+            if let Some(cwd) = self.get_cwd() {
                 t!(cvt(libc::chdir(cwd.as_ptr())));
             }
 

library/test/src/lib.rs

@@ -650,8 +650,8 @@ fn run_test_in_process(
     io::set_output_capture(None);
 
     let test_result = match result {
-        Ok(()) => calc_result(&desc, Ok(()), &time_opts, &exec_time),
-        Err(e) => calc_result(&desc, Err(e.as_ref()), &time_opts, &exec_time),
+        Ok(()) => calc_result(&desc, Ok(()), time_opts.as_ref(), exec_time.as_ref()),
+        Err(e) => calc_result(&desc, Err(e.as_ref()), time_opts.as_ref(), exec_time.as_ref()),
     };
     let stdout = data.lock().unwrap_or_else(|e| e.into_inner()).to_vec();
     let message = CompletedTest::new(id, desc, test_result, exec_time, stdout);
@@ -712,7 +712,8 @@ fn spawn_test_subprocess(
         formatters::write_stderr_delimiter(&mut test_output, &desc.name);
         test_output.extend_from_slice(&stderr);
 
-        let result = get_result_from_exit_code(&desc, status, &time_opts, &exec_time);
+        let result =
+            get_result_from_exit_code(&desc, status, time_opts.as_ref(), exec_time.as_ref());
         (result, test_output, exec_time)
     })();
 
@@ -724,8 +725,8 @@ fn run_test_in_spawned_subprocess(desc: TestDesc, runnable_test: RunnableTest) -
     let builtin_panic_hook = panic::take_hook();
     let record_result = Arc::new(move |panic_info: Option<&'_ PanicHookInfo<'_>>| {
         let test_result = match panic_info {
-            Some(info) => calc_result(&desc, Err(info.payload()), &None, &None),
-            None => calc_result(&desc, Ok(()), &None, &None),
+            Some(info) => calc_result(&desc, Err(info.payload()), None, None),
+            None => calc_result(&desc, Ok(()), None, None),
         };
 
         // We don't support serializing TrFailedMsg, so just

library/test/src/test_result.rs

@@ -42,8 +42,8 @@ pub enum TestResult {
 pub fn calc_result<'a>(
     desc: &TestDesc,
     task_result: Result<(), &'a (dyn Any + 'static + Send)>,
-    time_opts: &Option<time::TestTimeOptions>,
-    exec_time: &Option<time::TestExecTime>,
+    time_opts: Option<&time::TestTimeOptions>,
+    exec_time: Option<&time::TestExecTime>,
 ) -> TestResult {
     let result = match (&desc.should_panic, task_result) {
         (&ShouldPanic::No, Ok(())) | (&ShouldPanic::Yes, Err(_)) => TestResult::TrOk,
@@ -96,8 +96,8 @@ pub fn calc_result<'a>(
 pub fn get_result_from_exit_code(
     desc: &TestDesc,
     status: ExitStatus,
-    time_opts: &Option<time::TestTimeOptions>,
-    exec_time: &Option<time::TestExecTime>,
+    time_opts: Option<&time::TestTimeOptions>,
+    exec_time: Option<&time::TestExecTime>,
 ) -> TestResult {
     let result = match status.code() {
         Some(TR_OK) => TestResult::TrOk,