Use objc2-metal with metal naming scheme

To keep the diff smaller and easier to review, this uses a temporary
fork of `objc2-metal` and `objc2-quartz-core` whose methods use the
naming scheme of the `metal` crate.

One particular difficult part with this is that the `metal` crate has
several methods where the order of the arguments are swapped relative
to the corresponding Objective-C methods.

This includes most perilously (since these have both an offset and an
index argument, both of which are integers):
- `set_bytes`
- `set_vertex_bytes`
- `set_fragment_bytes`
- `set_buffer`
- `set_vertex_buffer`
- `set_fragment_buffer`
- `set_threadgroup_memory_length`

But also:
- `set_vertex_texture`
- `set_fragment_texture`
- `set_sampler_state`
- `set_vertex_sampler_state`
- `set_fragment_sampler_state`

Author: madsmtm

CHANGELOG.md

@@ -107,6 +107,9 @@ By @stefnotch in [#5410](https://github.com/gfx-rs/wgpu/pull/5410)
 
 - Fix enablement of subgroup ops extension on Vulkan devices that don't support Vulkan 1.3. By @cwfitzgerald in [#5624](https://github.com/gfx-rs/wgpu/pull/5624).
 
+#### Metal
+- Use autogenerated `objc2` bindings internally, which should resolve a lot of leaks and unsoundness. By @madsmtm in [#5641](https://github.com/gfx-rs/wgpu/pull/5641).
+
 #### GLES / OpenGL
 
 -  Fix regression on OpenGL (EGL) where non-sRGB still used sRGB [#5642](https://github.com/gfx-rs/wgpu/pull/5642)

Cargo.lock

@@ -192,6 +192,13 @@ termcolor = "1.4.1"
 #web-sys = { path = "../wasm-bindgen/crates/web-sys" }
 #js-sys = { path = "../wasm-bindgen/crates/js-sys" }
 #wasm-bindgen = { path = "../wasm-bindgen" }
+block2 = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc2 = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc2-encode = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc-sys = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc2-foundation = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc2-quartz-core = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
+objc2-metal = { git = "https://github.com/madsmtm/objc2", branch = "metal-wgpu" }
 
 [profile.release]
 lto = "thin"

Cargo.toml

@@ -18,10 +18,9 @@ rust-version = "1.74"
 [package.metadata.docs.rs]
 # Ideally we would enable all the features.
 #
-# However, the metal features fail to be documented because the docs.rs runner cross-compiling under
-# x86_64-unknown-linux-gnu and metal-rs cannot compile in that environment at the moment. The same applies
-# for the dx12 feature.
-features = ["vulkan", "gles", "renderdoc"]
+# However, the dx12 features fail to be documented because the docs.rs runner cross-compiling under
+# x86_64-unknown-linux-gnu cannot compile in that environment at the moment.
+features = ["metal", "vulkan", "gles", "renderdoc"]
 rustdoc-args = ["--cfg", "docsrs"]
 targets = [
     "x86_64-unknown-linux-gnu",
@@ -37,7 +36,7 @@ ignored = ["cfg_aliases"]
 [lib]
 
 [features]
-metal = ["naga/msl-out", "dep:block"]
+metal = ["naga/msl-out"]
 vulkan = [
     "naga/spv-out",
     "dep:ash",
@@ -156,11 +155,50 @@ d3d12 = { path = "../d3d12/", version = "0.20.0", optional = true, features = [
 
 [target.'cfg(any(target_os="macos", target_os="ios"))'.dependencies]
 # backend: Metal
-block = { version = "0.1", optional = true }
-
-metal = { version = "0.28.0" }
-objc = "0.2.5"
-core-graphics-types = "0.1"
+block2 = "0.5.1"
+objc2 = "0.5.2"
+objc2-foundation = { version = "0.2.2", features = [
+    "NSError",
+    "NSGeometry",
+    "NSProcessInfo",
+    "NSRange",
+    "NSString",
+] }
+objc2-metal = { version = "0.2.2", features = [
+    "block2",
+    "MTLBlitCommandEncoder",
+    "MTLBlitPass",
+    "MTLBuffer",
+    "MTLCaptureManager",
+    "MTLCaptureScope",
+    "MTLCommandBuffer",
+    "MTLCommandEncoder",
+    "MTLCommandQueue",
+    "MTLComputeCommandEncoder",
+    "MTLComputePass",
+    "MTLComputePipeline",
+    "MTLCounters",
+    "MTLDepthStencil",
+    "MTLDevice",
+    "MTLDrawable",
+    "MTLLibrary",
+    "MTLPipeline",
+    "MTLPixelFormat",
+    "MTLRenderCommandEncoder",
+    "MTLRenderPass",
+    "MTLRenderPipeline",
+    "MTLResource",
+    "MTLSampler",
+    "MTLStageInputOutputDescriptor",
+    "MTLTexture",
+    "MTLTypes",
+    "MTLVertexDescriptor",
+] }
+objc2-quartz-core = { version = "0.2.2", features = [
+    "CALayer",
+    "CAMetalLayer",
+    "objc2-metal",
+] }
 
 [target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dependencies]
 wasm-bindgen = "0.2.87"

wgpu-hal/Cargo.toml

@@ -1261,10 +1261,11 @@ impl crate::Surface for Surface {
                         let window_ptr = handle.ns_view.as_ptr();
                         #[cfg(target_os = "macos")]
                         let window_ptr = {
-                            use objc::{msg_send, runtime::Object, sel, sel_impl};
+                            use objc2::msg_send;
+                            use objc2::runtime::AnyObject;
                             // ns_view always have a layer and don't need to verify that it exists.
-                            let layer: *mut Object =
-                                msg_send![handle.ns_view.as_ptr() as *mut Object, layer];
+                            let layer: *mut AnyObject =
+                                msg_send![handle.ns_view.as_ptr() as *mut AnyObject, layer];
                             layer as *mut ffi::c_void
                         };
                         window_ptr