Fix several clippy lints

anvil/src/input_handler.rs

@@ -46,7 +46,7 @@ impl<Backend> AnvilState<Backend> {
             // only process special actions on key press, not release
             return KeyAction::None;
         }
-        return action;
+        action
     }
 
     fn on_pointer_button<B: InputBackend>(&mut self, evt: B::PointerButtonEvent) {
@@ -223,7 +223,7 @@ impl AnvilState<UdevData> {
     }
 
     fn clamp_coords(&self, pos: (f64, f64)) -> (f64, f64) {
-        if self.backend_data.output_map.len() == 0 {
+        if self.backend_data.output_map.is_empty() {
             return pos;
         }
 

anvil/src/winit.rs

@@ -189,7 +189,7 @@ pub fn run_winit(
                     Ok(())
                 })
                 .map_err(Into::<SwapBuffersError>::into)
-                .and_then(|x| x.into());
+                .and_then(|x| x);
 
             renderer.window().set_cursor_visible(cursor_visible);
 

src/backend/allocator/dmabuf.rs

@@ -152,7 +152,7 @@ impl DmabufBuilder {
     ///
     /// Returns `None` if the builder has no planes attached.
     pub fn build(mut self) -> Option<Dmabuf> {
-        if self.internal.planes.len() == 0 {
+        if self.internal.planes.is_empty() {
             return None;
         }
 
@@ -167,7 +167,7 @@ impl Dmabuf {
     // Note: the `src` Buffer is only used a reference for size and format.
     // The contents are determined by the provided file descriptors, which
     // do not need to refer to the same buffer `src` does.
-    pub fn new_from_buffer(src: &impl Buffer, flags: DmabufFlags) -> DmabufBuilder {
+    pub fn builder_from_buffer(src: &impl Buffer, flags: DmabufFlags) -> DmabufBuilder {
         DmabufBuilder {
             internal: DmabufInternal {
                 planes: Vec::with_capacity(MAX_PLANES),
@@ -179,8 +179,8 @@ impl Dmabuf {
         }
     }
 
-    /// Create a new Dmabuf
-    pub fn new(width: u32, height: u32, format: Fourcc, flags: DmabufFlags) -> DmabufBuilder {
+    /// Create a new Dmabuf builder
+    pub fn builder(width: u32, height: u32, format: Fourcc, flags: DmabufFlags) -> DmabufBuilder {
         DmabufBuilder {
             internal: DmabufInternal {
                 planes: Vec::with_capacity(MAX_PLANES),
@@ -198,17 +198,17 @@ impl Dmabuf {
     }
 
     /// Returns raw handles of the planes of this buffer
-    pub fn handles<'a>(&'a self) -> impl Iterator<Item = RawFd> + 'a {
+    pub fn handles(&self) -> impl Iterator<Item = RawFd> + '_ {
         self.0.planes.iter().map(|p| *p.fd.as_ref().unwrap())
     }
 
     /// Returns offsets for the planes of this buffer
-    pub fn offsets<'a>(&'a self) -> impl Iterator<Item = u32> + 'a {
+    pub fn offsets(&self) -> impl Iterator<Item = u32> + '_ {
         self.0.planes.iter().map(|p| p.offset)
     }
 
     /// Returns strides for the planes of this buffer
-    pub fn strides<'a>(&'a self) -> impl Iterator<Item = u32> + 'a {
+    pub fn strides(&self) -> impl Iterator<Item = u32> + '_ {
         self.0.planes.iter().map(|p| p.stride)
     }
 

src/backend/allocator/gbm.rs

@@ -99,7 +99,7 @@ impl<T> AsDmabuf for GbmBuffer<T> {
             return Err(GbmConvertError::InvalidFD);
         }
 
-        let mut builder = Dmabuf::new_from_buffer(self, DmabufFlags::empty());
+        let mut builder = Dmabuf::builder_from_buffer(self, DmabufFlags::empty());
         for idx in 0..planes {
             builder.add_plane(
                 self.fd()?,

src/backend/drm/render.rs

@@ -172,10 +172,10 @@ where
                         debug!(logger, "Success, choosen format: {:?}", format);
                         let buffers = Buffers::new(drm.clone(), gbm, buffer);
                         Ok(DrmRenderSurface {
-                            drm,
-                            renderer,
-                            swapchain,
                             buffers,
+                            swapchain,
+                            renderer,
+                            drm,
                         })
                     }
                     Err(err) => {
@@ -337,12 +337,14 @@ impl<A: AsRawFd + 'static> Drop for FbHandle<A> {
     }
 }
 
+type DmabufSlot<B, D> = Slot<B, (Dmabuf, BufferObject<FbHandle<D>>)>;
+
 struct Buffers<D: AsRawFd + 'static, B: Buffer> {
     gbm: GbmDevice<gbm::FdWrapper>,
     drm: Arc<DrmSurface<D>>,
-    _current_fb: Slot<B, (Dmabuf, BufferObject<FbHandle<D>>)>,
-    pending_fb: Option<Slot<B, (Dmabuf, BufferObject<FbHandle<D>>)>>,
-    queued_fb: Option<Slot<B, (Dmabuf, BufferObject<FbHandle<D>>)>>,
+    _current_fb: DmabufSlot<B, D>,
+    pending_fb: Option<DmabufSlot<B, D>>,
+    queued_fb: Option<DmabufSlot<B, D>>,
 }
 
 impl<D, B> Buffers<D, B>

src/backend/drm/surface/mod.rs

@@ -280,7 +280,7 @@ impl<A: AsRawFd + 'static> DrmSurface<A> {
                 .iter()
                 .find(|handle| {
                     // get information of that property
-                    if let Some(info) = self.get_property(**handle).ok() {
+                    if let Ok(info) = self.get_property(**handle) {
                         // to find out, if we got the handle of the "IN_FORMATS" property ...
                         if info.name().to_str().map(|x| x == "IN_FORMATS").unwrap_or(false) {
                             // so we can use that to get formats

src/backend/egl/native.rs

@@ -120,7 +120,7 @@ impl<'a> Debug for EGLPlatform<'a> {
 /// Trait describing platform specific functionality to create a valid `EGLDisplay` using the `EGL_EXT_platform_base`(https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_platform_base.txt) extension.
 pub trait EGLNativeDisplay: Send {
     /// List of supported platforms that can be used to create a display using [`eglGetPlatformDisplayEXT`](https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_platform_base.txt)
-    fn supported_platforms<'a>(&'a self) -> Vec<EGLPlatform<'a>>;
+    fn supported_platforms(&self) -> Vec<EGLPlatform<'_>>;
 
     /// Type of surfaces created
     fn surface_type(&self) -> ffi::EGLint {
@@ -130,7 +130,7 @@ pub trait EGLNativeDisplay: Send {
 
 #[cfg(feature = "backend_gbm")]
 impl<A: AsRawFd + Send + 'static> EGLNativeDisplay for GbmDevice<A> {
-    fn supported_platforms<'a>(&'a self) -> Vec<EGLPlatform<'a>> {
+    fn supported_platforms(&self) -> Vec<EGLPlatform<'_>> {
         vec![
             // see: https://www.khronos.org/registry/EGL/extensions/KHR/EGL_KHR_platform_gbm.txt
             egl_platform!(PLATFORM_GBM_KHR, self.as_raw(), &["EGL_KHR_platform_gbm"]),
@@ -142,7 +142,7 @@ impl<A: AsRawFd + Send + 'static> EGLNativeDisplay for GbmDevice<A> {
 
 #[cfg(feature = "backend_winit")]
 impl EGLNativeDisplay for WinitWindow {
-    fn supported_platforms<'a>(&'a self) -> Vec<EGLPlatform<'a>> {
+    fn supported_platforms(&self) -> Vec<EGLPlatform<'_>> {
         if let Some(display) = self.wayland_display() {
             vec![
                 // see: https://www.khronos.org/registry/EGL/extensions/KHR/EGL_KHR_platform_wayland.txt

src/backend/renderer/gles2/mod.rs

@@ -537,7 +537,7 @@ impl ImportShm for Gles2Renderer {
                         unsafe { self.gl.GenTextures(1, &mut tex) };
                         // new texture, upload in full
                         upload_full = true;
-                        let texture = Rc::new(Gles2TextureInternal {
+                        Rc::new(Gles2TextureInternal {
                             texture: tex,
                             texture_kind: shader_idx,
                             is_external: false,
@@ -546,8 +546,7 @@ impl ImportShm for Gles2Renderer {
                             height: height as u32,
                             egl_images: None,
                             destruction_callback_sender: self.destruction_callback_sender.clone(),
-                        });
-                        texture
+                        })
                     }),
             );
 

src/utils/mod.rs

@@ -3,3 +3,15 @@
 mod rectangle;
 
 pub use self::rectangle::Rectangle;
+
+/// This resource is not managed by Smithay
+#[derive(Debug)]
+pub struct UnmanagedResource;
+
+impl std::fmt::Display for UnmanagedResource {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("This resource is not managed by Smithay.")
+    }
+}
+
+impl std::error::Error for UnmanagedResource {}

src/wayland/compositor/handlers.rs

@@ -7,8 +7,8 @@ use wayland_server::{
 
 use super::{
     tree::{Location, SurfaceData},
-    BufferAssignment, CompositorToken, Damage, Rectangle, RectangleKind, RegionAttributes, Role, RoleType,
-    SubsurfaceRole, SurfaceEvent,
+    AlreadyHasRole, BufferAssignment, CompositorToken, Damage, Rectangle, RectangleKind, RegionAttributes,
+    Role, RoleType, SubsurfaceRole, SurfaceEvent,
 };
 
 /*
@@ -65,11 +65,11 @@ impl<R> SurfaceImplem<R>
 where
     R: 'static,
 {
-    fn receive_surface_request<'a>(
+    fn receive_surface_request(
         &mut self,
         req: wl_surface::Request,
         surface: wl_surface::WlSurface,
-        ddata: DispatchData<'a>,
+        ddata: DispatchData<'_>,
     ) {
         match req {
             wl_surface::Request::Attach { buffer, x, y } => {
@@ -196,7 +196,7 @@ where
 {
     subcompositor.quick_assign(move |subcompositor, request, _| match request {
         wl_subcompositor::Request::GetSubsurface { id, surface, parent } => {
-            if let Err(()) = SurfaceData::<R>::set_parent(&surface, &parent) {
+            if let Err(AlreadyHasRole) = SurfaceData::<R>::set_parent(&surface, &parent) {
                 subcompositor.as_ref().post_error(
                     wl_subcompositor::Error::BadSurface as u32,
                     "Surface already has a role.".into(),

src/wayland/compositor/mod.rs

@@ -76,7 +76,7 @@ mod tree;
 
 pub use self::tree::TraversalAction;
 use self::{
-    roles::{Role, RoleType, WrongRole},
+    roles::{AlreadyHasRole, Role, RoleType, WrongRole},
     tree::SurfaceData,
 };
 use crate::utils::Rectangle;
@@ -433,7 +433,7 @@ impl<R: RoleType + 'static> CompositorToken<R> {
     ///
     /// If the surface is not managed by the `CompositorGlobal` that provided this token, this
     /// will panic (having more than one compositor is not supported).
-    pub fn give_role<RoleData>(self, surface: &WlSurface) -> Result<(), ()>
+    pub fn give_role<RoleData>(self, surface: &WlSurface) -> Result<(), AlreadyHasRole>
     where
         R: Role<RoleData>,
         RoleData: Default,

src/wayland/compositor/roles.rs

@@ -92,6 +92,30 @@
 #[derive(Debug)]
 pub struct WrongRole;
 
+impl std::fmt::Display for WrongRole {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("Wrong role for surface.")
+    }
+}
+
+impl std::error::Error for WrongRole {}
+
+/// An error type signifying that the surface already has a role and
+/// cannot be assigned an other
+///
+/// Generated if you attempt a role operation on a surface that does
+/// not have the role you asked for.
+#[derive(Debug)]
+pub struct AlreadyHasRole;
+
+impl std::fmt::Display for AlreadyHasRole {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("Surface already has a role.")
+    }
+}
+
+impl std::error::Error for AlreadyHasRole {}
+
 /// A trait representing a type that can manage surface roles
 pub trait RoleType {
     /// Check if the associated surface has a role
@@ -126,11 +150,11 @@ pub trait Role<R>: RoleType {
     /// Set the role for the associated surface with default associated data
     ///
     /// Fails if the surface already has a role
-    fn set(&mut self) -> Result<(), ()>
+    fn set(&mut self) -> Result<(), AlreadyHasRole>
     where
         R: Default,
     {
-        self.set_with(Default::default()).map_err(|_| ())
+        self.set_with(Default::default()).map_err(|_| AlreadyHasRole)
     }
 
     /// Set the role for the associated surface with given data

src/wayland/compositor/tree.rs

@@ -127,7 +127,7 @@ impl<R: RoleType + 'static> SurfaceData<R> {
     }
 
     /// Register that this surface has a role, fails if it already has one
-    pub fn give_role<RoleData>(surface: &WlSurface) -> Result<(), ()>
+    pub fn give_role<RoleData>(surface: &WlSurface) -> Result<(), AlreadyHasRole>
     where
         R: Role<RoleData>,
         RoleData: Default,
@@ -215,12 +215,12 @@ impl<R: RoleType + Role<SubsurfaceRole> + 'static> SurfaceData<R> {
     ///
     /// if this surface already has a role, does nothing and fails, otherwise
     /// its role is now to be a subsurface
-    pub fn set_parent(child: &WlSurface, parent: &WlSurface) -> Result<(), ()> {
+    pub fn set_parent(child: &WlSurface, parent: &WlSurface) -> Result<(), AlreadyHasRole> {
         debug_assert!(child.as_ref().is_alive());
         debug_assert!(parent.as_ref().is_alive());
         // ensure the child is not already a parent of the parent
         if Self::is_ancestor(child, parent) {
-            return Err(());
+            return Err(AlreadyHasRole);
         }
 
         // change child's parent

src/wayland/data_device/data_source.rs

@@ -44,9 +44,9 @@ pub(crate) fn implement_data_source(src: Main<WlDataSource>) -> WlDataSource {
 pub fn with_source_metadata<T, F: FnOnce(&SourceMetadata) -> T>(
     source: &WlDataSource,
     f: F,
-) -> Result<T, ()> {
+) -> Result<T, crate::utils::UnmanagedResource> {
     match source.as_ref().user_data().get::<RefCell<SourceMetadata>>() {
         Some(data) => Ok(f(&data.borrow())),
-        None => Err(()),
+        None => Err(crate::utils::UnmanagedResource),
     }
 }

src/wayland/data_device/dnd_grab.rs

@@ -251,7 +251,7 @@ fn implement_dnd_data_offer(
         match req {
             Request::Accept { mime_type, .. } => {
                 if let Some(mtype) = mime_type {
-                    if let Err(()) = with_source_metadata(&source, |meta| {
+                    if let Err(crate::utils::UnmanagedResource) = with_source_metadata(&source, |meta| {
                         data.accepted = meta.mime_types.contains(&mtype);
                     }) {
                         data.accepted = false;

src/wayland/dmabuf/mod.rs

@@ -259,7 +259,7 @@ where
             return;
         }
 
-        let mut buf = Dmabuf::new(
+        let mut buf = Dmabuf::builder(
             width as u32,
             height as u32,
             format,
@@ -277,7 +277,7 @@ where
             None => {
                 params.as_ref().post_error(
                     ParamError::Incomplete as u32,
-                    format!("Provided buffer is incomplete, it has zero planes"),
+                    "Provided buffer is incomplete, it has zero planes".to_string(),
                 );
                 return;
             }
@@ -305,6 +305,7 @@ where
         }
     }
 
+    #[allow(clippy::clippy::too_many_arguments)]
     fn create_immed<'a>(
         &mut self,
         params: &BufferParams,
@@ -348,7 +349,7 @@ where
             return;
         }
 
-        let mut buf = Dmabuf::new(
+        let mut buf = Dmabuf::builder(
             width as u32,
             height as u32,
             format,
@@ -366,7 +367,7 @@ where
             None => {
                 params.as_ref().post_error(
                     ParamError::Incomplete as u32,
-                    format!("Provided buffer is incomplete, it has zero planes"),
+                    "Provided buffer is incomplete, it has zero planes".to_string(),
                 );
                 return;
             }

src/wayland/explicit_synchronization/mod.rs

@@ -61,7 +61,7 @@
 //!                the contents of sync_state
 //!             */
 //!         },
-//!         Err(()) => {
+//!         Err(NoExplicitSync) => {
 //!             /* This surface is not explicitly synchronized, nothing more to do
 //!             */
 //!         }
@@ -155,6 +155,18 @@ pub enum ExplicitSyncError {
     NoBuffer,
 }
 
+/// This surface is not explicitly synchronized
+#[derive(Debug)]
+pub struct NoExplicitSync;
+
+impl std::fmt::Display for NoExplicitSync {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("The surface is not explicitly synchronized.")
+    }
+}
+
+impl std::error::Error for NoExplicitSync {}
+
 /// Retrieve the explicit synchronization state commited by the client
 ///
 /// This state can contain an acquire fence and a release object, for synchronization (see module-level docs).
@@ -163,12 +175,14 @@ pub enum ExplicitSyncError {
 /// should always call it on surface commit to avoid getting out-of-sync with the client.
 ///
 /// This function returns an error if the client has not setup explicit synchronization for this surface.
-pub fn get_explicit_synchronization_state(attrs: &mut SurfaceAttributes) -> Result<ExplicitSyncState, ()> {
+pub fn get_explicit_synchronization_state(
+    attrs: &mut SurfaceAttributes,
+) -> Result<ExplicitSyncState, NoExplicitSync> {
     attrs
         .user_data
         .get::<ESUserData>()
         .and_then(|s| s.take_state())
-        .ok_or(())
+        .ok_or(NoExplicitSync)
 }
 
 /// Send a synchronization error to a client

src/xwayland/xserver.rs

@@ -192,7 +192,7 @@ fn launch<Data: Any>(inner: &Rc<RefCell<Inner<Data>>>) -> std::io::Result<()> {
             client.data_map().insert_if_missing(|| idle_inner.clone());
             client.add_destructor(Filter::new(|e: Arc<_>, _, _| client_destroy::<Data>(&e)));
 
-            instance.wayland_client = Some(client.clone());
+            instance.wayland_client = Some(client);
         }
     });