chore: fix clippy warnings

The new version of clippy in the CI suggested several improvements.
Some fixed with `clippy --fix`, some by hand.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>

staging/vhost-device-video/src/main.rs

@@ -104,6 +104,7 @@ fn main() -> Result<()> {
 #[cfg(test)]
 mod tests {
     use assert_matches::assert_matches;
+    #[cfg(feature = "v4l2-decoder")]
     use rstest::*;
     use tempfile::tempdir;
 
@@ -125,6 +126,7 @@ mod tests {
         backend: BackendType::Null,
     })]
     // Selecting different decoder
+    #[cfg(feature = "v4l2-decoder")]
     #[case::set_v4l2_decoder(vec![" ", "--socket-path", "long-video.sock", "-b", "v4l2-decoder"],
     VideoArgs {
         socket_path: "long-video.sock".into(),
@@ -137,6 +139,7 @@ mod tests {
         assert_eq!(VuVideoConfig::from(command_line), VuVideoConfig::from(args));
     }
 
+    #[cfg(feature = "v4l2-decoder")]
     #[test]
     fn test_fail_create_backend() {
         use vhu_video::VuVideoError;

staging/vhost-device-video/src/stream.rs

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0 or BSD-3-Clause
 
 // Null Backend does not use all stream capabilities
-#![cfg_attr(not(any(feature)), allow(dead_code))]
+#![cfg_attr(not(any(feature = "default")), allow(dead_code))]
 
 use std::{
     collections::HashMap,

vhost-device-i2c/src/vhu_i2c.rs

@@ -372,7 +372,7 @@ mod tests {
     // Prepares a single chain of descriptors
     fn prepare_desc_chain(
         start_addr: GuestAddress,
-        buf: &mut Vec<u8>,
+        buf: &mut [u8],
         flag: u32,
         client_addr: u16,
     ) -> I2cDescriptorChain {

vhost-device-scmi/src/devices/iio.rs

@@ -734,7 +734,7 @@ mod tests {
             let path = make_directory("_test");
             let directory = IIODirectory { path };
             for (file, content) in files.iter() {
-                fs::write(&directory.path.join(file), content).unwrap();
+                fs::write(directory.path.join(file), content).unwrap();
             }
             directory
         }

vhost-device-scsi/src/scsi/emulation/target.rs

@@ -58,7 +58,7 @@ impl EmulatedTarget {
         self.luns.push(logical_unit);
     }
 
-    pub(crate) fn luns(&self) -> impl Iterator<Item = u16> + ExactSizeIterator + '_ {
+    pub(crate) fn luns(&self) -> impl ExactSizeIterator<Item = u16> + '_ {
         // unwrap is safe: we limit LUNs at 256
         self.luns
             .iter()

vhost-device-scsi/src/scsi/emulation/tests/mod.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0 or BSD-3-Clause
 
-#![cfg(test)]
-
 mod bad_lun;
 mod generic;
 mod report_supported_operation_codes;

vhost-device-sound/src/audio_backends/pipewire/test_utils.rs

@@ -53,9 +53,9 @@ impl Drop for DbusSession {
 /// `PipewireTestHarness::new()`.
 #[non_exhaustive]
 pub struct PipewireTestHarness {
-    pub dbus: DbusSession,
+    pub _dbus: DbusSession,
     pub pipewire_child: Child,
-    pub tempdir: TempDir,
+    pub _tempdir: TempDir,
 }
 
 pub fn launch_pipewire(
@@ -92,9 +92,9 @@ impl PipewireTestHarness {
         std::env::set_var("XDG_RUNTIME_DIR", tempdir.path());
 
         Self {
-            dbus: dbus_session,
+            _dbus: dbus_session,
             pipewire_child,
-            tempdir,
+            _tempdir: tempdir,
         }
     }
 }

vhost-device-sound/src/stream.rs

@@ -42,7 +42,7 @@ type Result<T> = std::result::Result<T, Error>;
 /// - `SET PARAMETERS`
 ///
 ///   The driver negotiates the stream parameters (format, transport, etc) with
-/// the device.
+///   the device.
 ///
 ///   Possible valid transitions: `SET PARAMETERS`, `PREPARE`.
 ///
@@ -51,7 +51,7 @@ type Result<T> = std::result::Result<T, Error>;
 ///   The device prepares the stream (allocates resources, etc).
 ///
 ///   Possible valid transitions: `SET PARAMETERS`, `PREPARE`, `START`,
-/// `RELEASE`.   Output only: the driver transfers data for pre-buffing.
+///   `RELEASE`.   Output only: the driver transfers data for pre-buffing.
 ///
 /// - `START`
 ///

vhost-device-template/src/vhu_foo.rs

@@ -266,7 +266,7 @@ mod tests {
     fn prepare_descriptors(
         mut next_addr: u64,
         mem: &GuestMemoryLoadGuard<GuestMemoryMmap<()>>,
-        buf: &mut Vec<u8>,
+        buf: &mut [u8],
     ) -> Vec<Descriptor> {
         let mut descriptors = Vec::new();
         let mut index = 0;
@@ -317,7 +317,7 @@ mod tests {
     }
 
     // Prepares a single chain of descriptors
-    fn prepare_desc_chain(buf: &mut Vec<u8>) -> (VhostUserFooBackend, VringRwLock) {
+    fn prepare_desc_chain(buf: &mut [u8]) -> (VhostUserFooBackend, VringRwLock) {
         let (mut backend, mem, vring) = init();
         let mem_handle = mem.memory();
         let vq = MockSplitQueue::new(&*mem_handle, 16);
@@ -351,7 +351,7 @@ mod tests {
     // Prepares a chain of descriptors
     fn prepare_desc_chains(
         mem: &GuestMemoryAtomic<GuestMemoryMmap>,
-        buf: &mut Vec<u8>,
+        buf: &mut [u8],
     ) -> FooDescriptorChain {
         let mem_handle = mem.memory();
         let vq = MockSplitQueue::new(&*mem_handle, 16);

vhost-device-vsock/src/vhu_vsock.rs

@@ -4,7 +4,6 @@ use std::{
     collections::{HashMap, HashSet},
     io::{self, Result as IoResult},
     sync::{Arc, Mutex, RwLock},
-    u16, u32, u64, u8,
 };
 
 use log::warn;