refactor: satisfy clippy::missing_transmute_annotations (#6024)

* refactor(metal): satisfy `clippy::missing_transmute_annotations` * refactor(gles): satisfy `clippy::missing_transmute_annotations` * refactor(metal): `metal::Surface::view`: use `ptr::cast` instead of `as`
gfx-rs · Jul 24, 2024 · 7b2e08f · 7b2e08f
1 parent 9b680e6
commit 7b2e08f
Show file tree

Hide file tree

Showing 3 changed files with 32 additions and 16 deletions.
diff --git a/wgpu-core/src/instance.rs b/wgpu-core/src/instance.rs
@@ -577,9 +577,20 @@ impl Global {
             metal: Some(self.instance.metal.as_ref().map_or(
                 Err(CreateSurfaceError::BackendNotEnabled(Backend::Metal)),
                 |inst| {
-                    // we don't want to link to metal-rs for this
-                    #[allow(clippy::transmute_ptr_to_ref)]
-                    Ok(inst.create_surface_from_layer(unsafe { std::mem::transmute(layer) }))
+                    let layer = layer.cast();
+                    // SAFETY: We do this cast and deref. (rather than using `metal` to get the
+                    // object we want) to avoid direct coupling on the `metal` crate.
+                    //
+                    // To wit, this pointer…
+                    //
+                    // - …is properly aligned.
+                    // - …is dereferenceable to a `MetalLayerRef` as an invariant of the `metal`
+                    //   field.
+                    // - …points to an _initialized_ `MetalLayerRef`.
+                    // - …is only ever aliased via an immutable reference that lives within this
+                    //   lexical scope.
+                    let layer = unsafe { &*layer };
+                    Ok(inst.create_surface_from_layer(layer))
                 },
             )?),
             #[cfg(dx12)]

diff --git a/wgpu-hal/src/gles/device.rs b/wgpu-hal/src/gles/device.rs
@@ -9,8 +9,6 @@ use std::{
 };
 
 use arrayvec::ArrayVec;
-#[cfg(native)]
-use std::mem;
 use std::sync::atomic::Ordering;
 
 type ShaderStage<'a> = (
@@ -178,9 +176,7 @@ impl super::Device {
         let raw = unsafe { gl.create_shader(target) }.unwrap();
         #[cfg(native)]
         if gl.supports_debug() {
-            //TODO: remove all transmutes from `object_label`
-            // https://github.com/grovesNL/glow/issues/186
-            let name = unsafe { mem::transmute(raw) };
+            let name = raw.0.get();
             unsafe { gl.object_label(glow::SHADER, name, label) };
         }
 
@@ -366,7 +362,7 @@ impl super::Device {
         #[cfg(native)]
         if let Some(label) = label {
             if private_caps.contains(PrivateCapabilities::DEBUG_FNS) {
-                let name = unsafe { mem::transmute(program) };
+                let name = program.0.get();
                 unsafe { gl.object_label(glow::PROGRAM, name, Some(label)) };
             }
         }
@@ -621,7 +617,7 @@ impl crate::Device for super::Device {
                 .private_caps
                 .contains(PrivateCapabilities::DEBUG_FNS)
             {
-                let name = unsafe { mem::transmute(raw) };
+                let name = raw.map_or(0, |buf| buf.0.get());
                 unsafe { gl.object_label(glow::BUFFER, name, Some(label)) };
             }
         }
@@ -768,7 +764,7 @@ impl crate::Device for super::Device {
                     .private_caps
                     .contains(PrivateCapabilities::DEBUG_FNS)
                 {
-                    let name = unsafe { mem::transmute(raw) };
+                    let name = raw.0.get();
                     unsafe { gl.object_label(glow::RENDERBUFFER, name, Some(label)) };
                 }
             }
@@ -936,7 +932,7 @@ impl crate::Device for super::Device {
                     .private_caps
                     .contains(PrivateCapabilities::DEBUG_FNS)
                 {
-                    let name = unsafe { mem::transmute(raw) };
+                    let name = raw.0.get();
                     unsafe { gl.object_label(glow::TEXTURE, name, Some(label)) };
                 }
             }
@@ -1088,7 +1084,7 @@ impl crate::Device for super::Device {
                 .private_caps
                 .contains(PrivateCapabilities::DEBUG_FNS)
             {
-                let name = unsafe { mem::transmute(raw) };
+                let name = raw.0.get();
                 unsafe { gl.object_label(glow::SAMPLER, name, Some(label)) };
             }
         }

diff --git a/wgpu-hal/src/metal/surface.rs b/wgpu-hal/src/metal/surface.rs
@@ -1,6 +1,6 @@
 #![allow(clippy::let_unit_value)] // `let () =` being used to constrain result type
 
-use std::{mem, os::raw::c_void, ptr::NonNull, sync::Once, thread};
+use std::{os::raw::c_void, ptr::NonNull, sync::Once, thread};
 
 use core_graphics_types::{
     base::CGFloat,
@@ -82,10 +82,19 @@ impl super::Surface {
         view: *mut c_void,
         delegate: Option<&HalManagedMetalLayerDelegate>,
     ) -> Self {
-        let view = view as *mut Object;
+        let view = view.cast::<Object>();
         let render_layer = {
             let layer = unsafe { Self::get_metal_layer(view, delegate) };
-            unsafe { mem::transmute::<_, &metal::MetalLayerRef>(layer) }
+            let layer = layer.cast::<metal::MetalLayerRef>();
+            // SAFETY: This pointer…
+            //
+            // - …is properly aligned.
+            // - …is dereferenceable to a `MetalLayerRef` as an invariant of the `metal`
+            //   field.
+            // - …points to an _initialized_ `MetalLayerRef`.
+            // - …is only ever aliased via an immutable reference that lives within this
+            //   lexical scope.
+            unsafe { &*layer }
         }
         .to_owned();
         let _: *mut c_void = msg_send![view, retain];