From ecbb2254b6edd7103d87cb039cd0b816598dbc2f Mon Sep 17 00:00:00 2001
From: dAxpeDDa <daxpedda@gmail.com>
Date: Fri, 10 Feb 2023 15:02:27 +0100
Subject: [PATCH 1/4] Remove `emscripten` crate features

---
 .github/workflows/ci.yml       |  6 ++--
 deno_webgpu/Cargo.toml         |  2 +-
 player/Cargo.toml              |  2 +-
 wgpu-core/Cargo.toml           |  3 --
 wgpu-core/src/conv.rs          |  2 +-
 wgpu-core/src/device/queue.rs  |  2 +-
 wgpu-hal/Cargo.toml            |  1 -
 wgpu-hal/examples/raw-gles.rs  |  6 ++--
 wgpu-hal/src/empty.rs          |  2 +-
 wgpu-hal/src/gles/command.rs   |  2 +-
 wgpu-hal/src/gles/device.rs    |  4 +--
 wgpu-hal/src/gles/egl.rs       | 31 +++++++++++----------
 wgpu-hal/src/gles/mod.rs       | 14 +++++-----
 wgpu-hal/src/gles/queue.rs     |  6 ++--
 wgpu-hal/src/lib.rs            |  2 +-
 wgpu/Cargo.toml                |  7 +----
 wgpu/src/backend/direct.rs     | 40 +++++++++++++++++----------
 wgpu/src/backend/mod.rs        | 22 ++++++++++++---
 wgpu/src/backend/web.rs        |  2 +-
 wgpu/src/context.rs            |  6 ++--
 wgpu/src/lib.rs                | 50 ++++++++++++++++++++++------------
 wgpu/tests/common/mod.rs       | 32 +++++++++++++++++-----
 wgpu/tests/external_texture.rs |  2 +-
 23 files changed, 150 insertions(+), 96 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 00c0858978..c95c31ad90 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -139,13 +139,13 @@ jobs:
           set -e
 
           # build for Emscripten/WebGL
-          cargo clippy --target ${{ matrix.target }} -p wgpu -p wgpu-hal --no-default-features --features webgl,emscripten
+          cargo clippy --target ${{ matrix.target }} -p wgpu -p wgpu-hal --no-default-features
 
           # build cube example
-          cargo clippy --target ${{ matrix.target }} --example cube --features webgl,emscripten
+          cargo clippy --target ${{ matrix.target }} --example cube
 
           # build raw-gles example
-          cargo clippy --target ${{ matrix.target }} --example raw-gles --features webgl,emscripten
+          cargo clippy --target ${{ matrix.target }} --example raw-gles
 
       - name: check native
         if: matrix.kind == 'native'
diff --git a/deno_webgpu/Cargo.toml b/deno_webgpu/Cargo.toml
index eeb012f41e..67b76d5ae3 100644
--- a/deno_webgpu/Cargo.toml
+++ b/deno_webgpu/Cargo.toml
@@ -35,6 +35,6 @@ workspace = true
 features = ["dx11", "dx12"]
 
 # We want the wgpu-core Vulkan backend on Unix (but not Emscripten) and Windows.
-[target.'cfg(any(windows, all(unix, not(target_arch = "emscripten"))))'.dependencies.wgpu-core]
+[target.'cfg(any(windows, all(unix, not(target_os = "emscripten"))))'.dependencies.wgpu-core]
 workspace = true
 features = ["vulkan"]
diff --git a/player/Cargo.toml b/player/Cargo.toml
index 0946dad9dd..01aaf02db4 100644
--- a/player/Cargo.toml
+++ b/player/Cargo.toml
@@ -37,7 +37,7 @@ features = ["metal"]
 workspace = true
 features = ["dx11", "dx12"]
 
-[target.'cfg(any(windows, all(unix, not(target_arch = "emscripten"), not(target_os = "ios"), not(target_os = "macos"))))'.dependencies.wgc]
+[target.'cfg(any(windows, all(unix, not(target_os = "emscripten"), not(target_os = "ios"), not(target_os = "macos"))))'.dependencies.wgc]
 workspace = true
 features = ["vulkan"]
 
diff --git a/wgpu-core/Cargo.toml b/wgpu-core/Cargo.toml
index 8f0c00babc..95a8133d11 100644
--- a/wgpu-core/Cargo.toml
+++ b/wgpu-core/Cargo.toml
@@ -35,9 +35,6 @@ dx12 = ["hal/dx12"]
 # https://renderdoc.org/
 renderdoc = ["hal/renderdoc"]
 
-# Compile for the Emscripten POSIX-in-a-web-page emulation environment.
-emscripten = ["hal/emscripten"]
-
 # Apply run-time checks, even in release builds. These are in addition
 # to the validation carried out at public APIs in all builds.
 strict_asserts = ["wgt/strict_asserts"]
diff --git a/wgpu-core/src/conv.rs b/wgpu-core/src/conv.rs
index 52daa335a6..43986c946e 100644
--- a/wgpu-core/src/conv.rs
+++ b/wgpu-core/src/conv.rs
@@ -34,7 +34,7 @@ pub fn is_valid_copy_dst_texture_format(
 }
 
 #[cfg_attr(
-    any(not(target_arch = "wasm32"), feature = "emscripten"),
+    any(not(target_arch = "wasm32"), target_os = "emscripten"),
     allow(unused)
 )]
 pub fn is_valid_external_image_copy_dst_texture_format(format: wgt::TextureFormat) -> bool {
diff --git a/wgpu-core/src/device/queue.rs b/wgpu-core/src/device/queue.rs
index e0cc9bf656..37b9104723 100644
--- a/wgpu-core/src/device/queue.rs
+++ b/wgpu-core/src/device/queue.rs
@@ -814,7 +814,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         Ok(())
     }
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     pub fn queue_copy_external_image_to_texture<A: HalApi>(
         &self,
         queue_id: id::QueueId,
diff --git a/wgpu-hal/Cargo.toml b/wgpu-hal/Cargo.toml
index 983031c2b4..e198ab7e8f 100644
--- a/wgpu-hal/Cargo.toml
+++ b/wgpu-hal/Cargo.toml
@@ -43,7 +43,6 @@ dx12 = ["naga/hlsl-out", "native", "bit-set", "range-alloc", "winapi/std", "wina
 windows_rs = ["gpu-allocator"]
 dxc_shader_compiler = ["hassle-rs"]
 renderdoc = ["libloading", "renderdoc-sys"]
-emscripten = ["gles"]
 
 [[example]]
 name = "halmark"
diff --git a/wgpu-hal/examples/raw-gles.rs b/wgpu-hal/examples/raw-gles.rs
index 4c793bba68..02857b9693 100644
--- a/wgpu-hal/examples/raw-gles.rs
+++ b/wgpu-hal/examples/raw-gles.rs
@@ -4,7 +4,7 @@
 //! Emscripten build:
 //! 1. install emsdk
 //! 2. build this example with cargo:
-//!    EMCC_CFLAGS="-g -s ERROR_ON_UNDEFINED_SYMBOLS=0 --no-entry -s FULL_ES3=1" cargo build --example raw-gles --target wasm32-unknown-emscripten --features emscripten,webgl
+//!    EMCC_CFLAGS="-g -s ERROR_ON_UNDEFINED_SYMBOLS=0 --no-entry -s FULL_ES3=1" cargo build --example raw-gles --target wasm32-unknown-emscripten
 //! 3. copy raw-gles.em.html into target directory and open it in browser:
 //!    cp wgpu-hal/examples/raw-gles.em.html target/wasm32-unknown-emscripten/debug/examples
 
@@ -66,7 +66,7 @@ fn main() {
     });
 }
 
-#[cfg(feature = "emscripten")]
+#[cfg(target_os = "emscripten")]
 fn main() {
     env_logger::init();
 
@@ -116,7 +116,7 @@ fn main() {
     fill_screen(&exposed, 640, 400);
 }
 
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 fn main() {}
 
 fn fill_screen(exposed: &hal::ExposedAdapter<hal::api::Gles>, width: u32, height: u32) {
diff --git a/wgpu-hal/src/empty.rs b/wgpu-hal/src/empty.rs
index 5e112b126b..1497acad91 100644
--- a/wgpu-hal/src/empty.rs
+++ b/wgpu-hal/src/empty.rs
@@ -264,7 +264,7 @@ impl crate::CommandEncoder<Api> for Encoder {
 
     unsafe fn copy_buffer_to_buffer<T>(&mut self, src: &Resource, dst: &Resource, regions: T) {}
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     unsafe fn copy_external_image_to_texture<T>(
         &mut self,
         src: &wgt::ImageCopyExternalImage,
diff --git a/wgpu-hal/src/gles/command.rs b/wgpu-hal/src/gles/command.rs
index 8076a13aeb..50e9f9fad3 100644
--- a/wgpu-hal/src/gles/command.rs
+++ b/wgpu-hal/src/gles/command.rs
@@ -309,7 +309,7 @@ impl crate::CommandEncoder<super::Api> for super::CommandEncoder {
         }
     }
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     unsafe fn copy_external_image_to_texture<T>(
         &mut self,
         src: &wgt::ImageCopyExternalImage,
diff --git a/wgpu-hal/src/gles/device.rs b/wgpu-hal/src/gles/device.rs
index f6921d2b69..19bf7843da 100644
--- a/wgpu-hal/src/gles/device.rs
+++ b/wgpu-hal/src/gles/device.rs
@@ -94,7 +94,7 @@ impl super::Device {
     /// - If `drop_guard` is [`None`], wgpu-hal will take ownership of the texture. If `drop_guard` is
     ///   [`Some`], the texture must be valid until the drop implementation
     ///   of the drop guard is called.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn texture_from_raw(
         &self,
         name: std::num::NonZeroU32,
@@ -125,7 +125,7 @@ impl super::Device {
     /// - If `drop_guard` is [`None`], wgpu-hal will take ownership of the renderbuffer. If `drop_guard` is
     ///   [`Some`], the renderbuffer must be valid until the drop implementation
     ///   of the drop guard is called.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn texture_from_raw_renderbuffer(
         &self,
         name: std::num::NonZeroU32,
diff --git a/wgpu-hal/src/gles/egl.rs b/wgpu-hal/src/gles/egl.rs
index b9eac71193..146eebdd7a 100644
--- a/wgpu-hal/src/gles/egl.rs
+++ b/wgpu-hal/src/gles/egl.rs
@@ -26,10 +26,10 @@ type WlDisplayConnectFun =
 
 type WlDisplayDisconnectFun = unsafe extern "system" fn(display: *const raw::c_void);
 
-#[cfg(not(feature = "emscripten"))]
+#[cfg(not(target_os = "emscripten"))]
 type EglInstance = egl::DynamicInstance<egl::EGL1_4>;
 
-#[cfg(feature = "emscripten")]
+#[cfg(target_os = "emscripten")]
 type EglInstance = egl::Instance<egl::Static>;
 
 type WlEglWindowCreateFun = unsafe extern "system" fn(
@@ -423,7 +423,7 @@ struct Inner {
     version: (i32, i32),
     supports_native_window: bool,
     config: egl::Config,
-    #[cfg_attr(feature = "emscripten", allow(dead_code))]
+    #[cfg_attr(target_os = "emscripten", allow(dead_code))]
     wl_display: Option<*mut raw::c_void>,
     /// Method by which the framebuffer should support srgb
     srgb_kind: SrgbFrameBufferKind,
@@ -535,7 +535,7 @@ impl Inner {
         // and creating dummy pbuffer surface if not.
         let pbuffer = if version >= (1, 5)
             || display_extensions.contains("EGL_KHR_surfaceless_context")
-            || cfg!(feature = "emscripten")
+            || cfg!(target_os = "emscripten")
         {
             log::info!("\tEGL context: +surfaceless");
             None
@@ -624,10 +624,10 @@ unsafe impl Sync for Instance {}
 
 impl crate::Instance<super::Api> for Instance {
     unsafe fn init(desc: &crate::InstanceDescriptor) -> Result<Self, crate::InstanceError> {
-        #[cfg(feature = "emscripten")]
+        #[cfg(target_os = "emscripten")]
         let egl_result: Result<EglInstance, egl::Error> = Ok(egl::Instance::new(egl::Static));
 
-        #[cfg(not(feature = "emscripten"))]
+        #[cfg(not(target_os = "emscripten"))]
         let egl_result = if cfg!(windows) {
             unsafe {
                 egl::DynamicInstance::<egl::EGL1_4>::load_required_from_filename("libEGL.dll")
@@ -674,10 +674,10 @@ impl crate::Instance<super::Api> for Instance {
             None
         };
 
-        #[cfg(not(feature = "emscripten"))]
+        #[cfg(not(target_os = "emscripten"))]
         let egl1_5 = egl.upcast::<egl::EGL1_5>();
 
-        #[cfg(feature = "emscripten")]
+        #[cfg(target_os = "emscripten")]
         let egl1_5: Option<&Arc<EglInstance>> = Some(&egl);
 
         let (display, wsi_library, wsi_kind) = if let (Some(library), Some(egl)) =
@@ -776,7 +776,10 @@ impl crate::Instance<super::Api> for Instance {
     ) -> Result<Surface, crate::InstanceError> {
         use raw_window_handle::RawWindowHandle as Rwh;
 
-        #[cfg_attr(any(target_os = "android", feature = "emscripten"), allow(unused_mut))]
+        #[cfg_attr(
+            any(target_os = "android", target_os = "emscripten"),
+            allow(unused_mut)
+        )]
         let mut inner = self.inner.lock();
 
         match (window_handle, display_handle) {
@@ -801,7 +804,7 @@ impl crate::Instance<super::Api> for Instance {
                     return Err(crate::InstanceError);
                 }
             }
-            #[cfg(not(feature = "emscripten"))]
+            #[cfg(not(target_os = "emscripten"))]
             (Rwh::Wayland(_), raw_window_handle::RawDisplayHandle::Wayland(display_handle)) => {
                 if inner
                     .wl_display
@@ -841,7 +844,7 @@ impl crate::Instance<super::Api> for Instance {
                     drop(old_inner);
                 }
             }
-            #[cfg(feature = "emscripten")]
+            #[cfg(target_os = "emscripten")]
             (Rwh::Web(_), _) => {}
             other => {
                 log::error!("Unsupported window: {:?}", other);
@@ -1087,7 +1090,7 @@ impl crate::Surface<super::Api> for Surface {
                         wl_window = Some(window);
                         window
                     }
-                    #[cfg(feature = "emscripten")]
+                    #[cfg(target_os = "emscripten")]
                     (WindowKind::Unknown, Rwh::Web(handle)) => handle.id as *mut std::ffi::c_void,
                     (WindowKind::Unknown, Rwh::Win32(handle)) => handle.hwnd,
                     (WindowKind::Unknown, Rwh::AppKit(handle)) => {
@@ -1140,10 +1143,10 @@ impl crate::Surface<super::Api> for Surface {
                 }
                 attributes.push(egl::ATTRIB_NONE as i32);
 
-                #[cfg(not(feature = "emscripten"))]
+                #[cfg(not(target_os = "emscripten"))]
                 let egl1_5 = self.egl.instance.upcast::<egl::EGL1_5>();
 
-                #[cfg(feature = "emscripten")]
+                #[cfg(target_os = "emscripten")]
                 let egl1_5: Option<&Arc<EglInstance>> = Some(&self.egl.instance);
 
                 // Careful, we can still be in 1.4 version even if `upcast` succeeds
diff --git a/wgpu-hal/src/gles/mod.rs b/wgpu-hal/src/gles/mod.rs
index 31fde089d9..2af4066419 100644
--- a/wgpu-hal/src/gles/mod.rs
+++ b/wgpu-hal/src/gles/mod.rs
@@ -57,9 +57,9 @@ To address this, we invalidate the vertex buffers based on:
 */
 
 ///cbindgen:ignore
-#[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+#[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
 mod egl;
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 mod web;
 
 mod adapter;
@@ -70,14 +70,14 @@ mod queue;
 
 use crate::{CopyExtent, TextureDescriptor};
 
-#[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+#[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
 pub use self::egl::{AdapterContext, AdapterContextLock};
-#[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+#[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
 use self::egl::{Instance, Surface};
 
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 pub use self::web::AdapterContext;
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 use self::web::{Instance, Surface};
 
 use arrayvec::ArrayVec;
@@ -680,7 +680,7 @@ enum Command {
         dst_target: BindTarget,
         copy: crate::BufferCopy,
     },
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     CopyExternalImageToTexture {
         src: wgt::ImageCopyExternalImage,
         dst: glow::Texture,
diff --git a/wgpu-hal/src/gles/queue.rs b/wgpu-hal/src/gles/queue.rs
index add1daeb74..9b0d2d2c74 100644
--- a/wgpu-hal/src/gles/queue.rs
+++ b/wgpu-hal/src/gles/queue.rs
@@ -379,7 +379,7 @@ impl super::Queue {
                     unsafe { gl.bind_buffer(copy_dst_target, None) };
                 }
             }
-            #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+            #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
             C::CopyExternalImageToTexture {
                 ref src,
                 dst,
@@ -1509,10 +1509,10 @@ impl crate::Queue<super::Api> for super::Queue {
         surface: &mut super::Surface,
         texture: super::Texture,
     ) -> Result<(), crate::SurfaceError> {
-        #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+        #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
         let gl = unsafe { &self.shared.context.get_without_egl_lock() };
 
-        #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+        #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
         let gl = &self.shared.context.glow_context;
 
         unsafe { surface.present(texture, gl) }
diff --git a/wgpu-hal/src/lib.rs b/wgpu-hal/src/lib.rs
index 3178e255af..58c70e3ac1 100644
--- a/wgpu-hal/src/lib.rs
+++ b/wgpu-hal/src/lib.rs
@@ -407,7 +407,7 @@ pub trait CommandEncoder<A: Api>: Send + Sync + fmt::Debug {
     /// Works with a single array layer.
     /// Note: `dst` current usage has to be `TextureUses::COPY_DST`.
     /// Note: the copy extent is in physical size (rounded to the block size)
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     unsafe fn copy_external_image_to_texture<T>(
         &mut self,
         src: &wgt::ImageCopyExternalImage,
diff --git a/wgpu/Cargo.toml b/wgpu/Cargo.toml
index cf377227ea..69cdbe5a8d 100644
--- a/wgpu/Cargo.toml
+++ b/wgpu/Cargo.toml
@@ -97,7 +97,6 @@ trace = ["serde", "wgc/trace"]
 replay = ["serde", "wgc/replay"]
 angle = ["wgc/angle"]
 webgl = ["hal", "wgc"]
-emscripten = ["webgl"]
 vulkan-portability = ["wgc/vulkan"]
 expose-ids = []
 
@@ -128,14 +127,10 @@ workspace = true
 features = ["dx11", "dx12"]
 
 # We want the wgpu-core Vulkan backend on Unix (but not Emscripten) and Windows.
-[target.'cfg(any(windows, all(unix, not(target_arch = "emscripten"), not(target_os = "ios"), not(target_os = "macos"))))'.dependencies.wgc]
+[target.'cfg(any(windows, all(unix, not(target_os = "emscripten"), not(target_os = "ios"), not(target_os = "macos"))))'.dependencies.wgc]
 workspace = true
 features = ["vulkan"]
 
-[target.'cfg(target_os = "emscripten")'.dependencies.wgc]
-workspace = true
-features = ["emscripten"]
-
 [dependencies.wgt]
 workspace = true
 
diff --git a/wgpu/src/backend/direct.rs b/wgpu/src/backend/direct.rs
index 844c827091..c4cc638f2d 100644
--- a/wgpu/src/backend/direct.rs
+++ b/wgpu/src/backend/direct.rs
@@ -41,7 +41,7 @@ impl fmt::Debug for Context {
 }
 
 impl Context {
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn from_hal_instance<A: wgc::hub::HalApi>(hal_instance: A::Instance) -> Self {
         Self(unsafe {
             wgc::hub::Global::from_hal_instance::<A>(
@@ -69,13 +69,13 @@ impl Context {
         &self.0
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub fn enumerate_adapters(&self, backends: wgt::Backends) -> Vec<wgc::id::AdapterId> {
         self.0
             .enumerate_adapters(wgc::instance::AdapterInputs::Mask(backends, |_| ()))
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn create_adapter_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_adapter: hal::ExposedAdapter<A>,
@@ -94,7 +94,7 @@ impl Context {
         }
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn create_device_from_hal<A: wgc::hub::HalApi>(
         &self,
         adapter: &wgc::id::AdapterId,
@@ -128,7 +128,11 @@ impl Context {
         Ok((device, queue))
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten", feature = "webgl"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        target_os = "emscripten",
+        feature = "webgl"
+    ))]
     pub unsafe fn create_texture_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_texture: A::Texture,
@@ -154,7 +158,7 @@ impl Context {
         }
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn device_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Device>) -> R, R>(
         &self,
         device: &Device,
@@ -166,7 +170,7 @@ impl Context {
         }
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn surface_as_hal_mut<
         A: wgc::hub::HalApi,
         F: FnOnce(Option<&mut A::Surface>) -> R,
@@ -182,7 +186,7 @@ impl Context {
         }
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn texture_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Texture>)>(
         &self,
         texture: &Texture,
@@ -194,7 +198,7 @@ impl Context {
         }
     }
 
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub fn generate_report(&self) -> wgc::hub::GlobalReport {
         self.0.generate_report()
     }
@@ -211,7 +215,11 @@ impl Context {
         }
     }
 
-    #[cfg(all(target_arch = "wasm32", feature = "webgl", not(feature = "emscripten")))]
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "webgl",
+        not(target_os = "emscripten")
+    ))]
     pub fn instance_create_surface_from_canvas(
         &self,
         canvas: &web_sys::HtmlCanvasElement,
@@ -226,7 +234,11 @@ impl Context {
         })
     }
 
-    #[cfg(all(target_arch = "wasm32", feature = "webgl", not(feature = "emscripten")))]
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "webgl",
+        not(target_os = "emscripten")
+    ))]
     pub fn instance_create_surface_from_offscreen_canvas(
         &self,
         canvas: &web_sys::OffscreenCanvas,
@@ -353,7 +365,7 @@ fn map_texture_copy_view(view: crate::ImageCopyTexture) -> wgc::command::ImageCo
 }
 
 #[cfg_attr(
-    any(not(target_arch = "wasm32"), feature = "emscripten"),
+    any(not(target_arch = "wasm32"), target_os = "emscripten"),
     allow(unused)
 )]
 fn map_texture_tagged_copy_view(
@@ -1408,7 +1420,7 @@ impl crate::Context for Context {
     fn device_drop(&self, device: &Self::DeviceId, _device_data: &Self::DeviceData) {
         let global = &self.0;
 
-        #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+        #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
         {
             match wgc::gfx_select!(device => global.device_poll(*device, wgt::Maintain::Wait)) {
                 Ok(_) => (),
@@ -2219,7 +2231,7 @@ impl crate::Context for Context {
         }
     }
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &Self::QueueId,
diff --git a/wgpu/src/backend/mod.rs b/wgpu/src/backend/mod.rs
index d28cc0c102..5680b6c5a6 100644
--- a/wgpu/src/backend/mod.rs
+++ b/wgpu/src/backend/mod.rs
@@ -1,9 +1,23 @@
-#[cfg(all(target_arch = "wasm32", not(feature = "webgl")))]
+#[cfg(all(
+    target_arch = "wasm32",
+    not(any(target_os = "emscripten", feature = "webgl"))
+))]
 mod web;
-#[cfg(all(target_arch = "wasm32", not(feature = "webgl")))]
+#[cfg(all(
+    target_arch = "wasm32",
+    not(any(target_os = "emscripten", feature = "webgl"))
+))]
 pub(crate) use web::Context;
 
-#[cfg(any(not(target_arch = "wasm32"), feature = "webgl"))]
+#[cfg(any(
+    not(target_arch = "wasm32"),
+    target_os = "emscripten",
+    feature = "webgl"
+))]
 mod direct;
-#[cfg(any(not(target_arch = "wasm32"), feature = "webgl"))]
+#[cfg(any(
+    not(target_arch = "wasm32"),
+    target_os = "emscripten",
+    feature = "webgl"
+))]
 pub(crate) use direct::Context;
diff --git a/wgpu/src/backend/web.rs b/wgpu/src/backend/web.rs
index f3b9383610..1b87355eaf 100644
--- a/wgpu/src/backend/web.rs
+++ b/wgpu/src/backend/web.rs
@@ -2394,7 +2394,7 @@ impl crate::context::Context for Context {
             );
     }
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &Self::QueueId,
diff --git a/wgpu/src/context.rs b/wgpu/src/context.rs
index 3fe71a122e..92b85a9a04 100644
--- a/wgpu/src/context.rs
+++ b/wgpu/src/context.rs
@@ -561,7 +561,7 @@ pub trait Context: Debug + Send + Sized + Sync {
         data_layout: ImageDataLayout,
         size: Extent3d,
     );
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &Self::QueueId,
@@ -1488,7 +1488,7 @@ pub(crate) trait DynContext: Debug + Send + Sync {
         data_layout: ImageDataLayout,
         size: Extent3d,
     );
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &ObjectId,
@@ -2884,7 +2884,7 @@ where
         Context::queue_write_texture(self, &queue, queue_data, texture, data, data_layout, size)
     }
 
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &ObjectId,
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index 9fd36fa2c7..7414c0e637 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -49,9 +49,9 @@ pub use wgt::{
 
 // wasm-only types, we try to keep as many types non-platform
 // specific, but these need to depend on web-sys.
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 pub use wgt::{ExternalImageSource, ImageCopyExternalImage};
-#[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 static_assertions::assert_impl_all!(ExternalImageSource: Send, Sync);
 
 /// Filter for error scopes.
@@ -1341,7 +1341,7 @@ impl Instance {
     /// # Safety
     ///
     /// Refer to the creation of wgpu-hal Instance for every backend.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn from_hal<A: wgc::hub::HalApi>(hal_instance: A::Instance) -> Self {
         Self {
             context: Arc::new(unsafe {
@@ -1360,7 +1360,11 @@ impl Instance {
     /// - The raw instance handle returned must not be manually destroyed.
     ///
     /// [`Instance`]: hal::Api::Instance
-    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        target_os = "emscripten",
+        feature = "webgl"
+    ))]
     pub unsafe fn as_hal<A: wgc::hub::HalApi>(&self) -> Option<&A::Instance> {
         unsafe {
             self.context
@@ -1380,7 +1384,11 @@ impl Instance {
     /// # Safety
     ///
     /// Refer to the creation of wgpu-core Instance.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        target_os = "emscripten",
+        feature = "webgl"
+    ))]
     pub unsafe fn from_core(core_instance: wgc::instance::Instance) -> Self {
         Self {
             context: Arc::new(unsafe {
@@ -1394,7 +1402,7 @@ impl Instance {
     /// # Arguments
     ///
     /// - `backends` - Backends from which to enumerate adapters.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub fn enumerate_adapters(&self, backends: Backends) -> impl Iterator<Item = Adapter> {
         let context = Arc::clone(&self.context);
         self.context
@@ -1433,7 +1441,7 @@ impl Instance {
     /// # Safety
     ///
     /// `hal_adapter` must be created from this instance internal handle.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn create_adapter_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_adapter: hal::ExposedAdapter<A>,
@@ -1575,7 +1583,7 @@ impl Instance {
     ///
     /// - On WebGL2: Will return an error if the browser does not support WebGL2,
     ///   or declines to provide GPU access (such as due to a resource shortage).
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     pub fn create_surface_from_canvas(
         &self,
         canvas: &web_sys::HtmlCanvasElement,
@@ -1611,7 +1619,7 @@ impl Instance {
     ///
     /// - On WebGL2: Will return an error if the browser does not support WebGL2,
     ///   or declines to provide GPU access (such as due to a resource shortage).
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     pub fn create_surface_from_offscreen_canvas(
         &self,
         canvas: &web_sys::OffscreenCanvas,
@@ -1659,7 +1667,7 @@ impl Instance {
     }
 
     /// Generates memory report.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub fn generate_report(&self) -> wgc::hub::GlobalReport {
         self.context
             .as_any()
@@ -1730,7 +1738,7 @@ impl Adapter {
     ///
     /// - `hal_device` must be created from this adapter internal handle.
     /// - `desc.features` must be a subset of `hal_device` features.
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn create_device_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_device: hal::OpenDevice<A>,
@@ -1780,7 +1788,11 @@ impl Adapter {
     /// - The raw handle passed to the callback must not be manually destroyed.
     ///
     /// [`A::Adapter`]: hal::Api::Adapter
-    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        target_os = "emscripten",
+        feature = "webgl"
+    ))]
     pub unsafe fn as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Adapter>) -> R, R>(
         &self,
         hal_adapter_callback: F,
@@ -2125,7 +2137,11 @@ impl Device {
     /// - `hal_texture` must be created from this device internal handle
     /// - `hal_texture` must be created respecting `desc`
     /// - `hal_texture` must be initialized
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten", feature = "webgl"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        target_os = "emscripten",
+        feature = "webgl"
+    ))]
     pub unsafe fn create_texture_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_texture: A::Texture,
@@ -2226,7 +2242,7 @@ impl Device {
     /// - The raw handle passed to the callback must not be manually destroyed.
     ///
     /// [`A::Device`]: hal::Api::Device
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Device>) -> R, R>(
         &self,
         hal_device_callback: F,
@@ -2564,7 +2580,7 @@ impl Texture {
     /// # Safety
     ///
     /// - The raw handle obtained from the hal Texture must not be manually destroyed
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Texture>)>(
         &self,
         hal_texture_callback: F,
@@ -3973,7 +3989,7 @@ impl Queue {
     }
 
     /// Schedule a copy of data from `image` into `texture`.
-    #[cfg(all(target_arch = "wasm32", not(feature = "emscripten")))]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     pub fn copy_external_image_to_texture(
         &self,
         source: &wgt::ImageCopyExternalImage,
@@ -4185,7 +4201,7 @@ impl Surface {
     /// # Safety
     ///
     /// - The raw handle obtained from the hal Surface must not be manually destroyed
-    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    #[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
     pub unsafe fn as_hal_mut<A: wgc::hub::HalApi, F: FnOnce(Option<&mut A::Surface>) -> R, R>(
         &mut self,
         hal_surface_callback: F,
diff --git a/wgpu/tests/common/mod.rs b/wgpu/tests/common/mod.rs
index d12ba5f3f9..319f60f7d4 100644
--- a/wgpu/tests/common/mod.rs
+++ b/wgpu/tests/common/mod.rs
@@ -340,12 +340,18 @@ fn initialize_adapter() -> (Adapter, SurfaceGuard) {
     let surface_guard;
     let compatible_surface;
 
-    #[cfg(not(all(target_arch = "wasm32", feature = "webgl")))]
+    #[cfg(not(all(
+        target_arch = "wasm32",
+        any(target_os = "emscripten", feature = "webgl")
+    )))]
     {
         surface_guard = SurfaceGuard {};
         compatible_surface = None;
     }
-    #[cfg(all(target_arch = "wasm32", feature = "webgl"))]
+    #[cfg(all(
+        target_arch = "wasm32",
+        any(target_os = "emscripten", feature = "webgl")
+    ))]
     {
         // On wasm, append a canvas to the document body for initializing the adapter
         let canvas = create_html_canvas();
@@ -371,14 +377,17 @@ fn initialize_adapter() -> (Adapter, SurfaceGuard) {
 }
 
 struct SurfaceGuard {
-    #[cfg(all(target_arch = "wasm32", feature = "webgl"))]
+    #[cfg(all(
+        target_arch = "wasm32",
+        any(target_os = "emscripten", feature = "webgl")
+    ))]
     canvas: web_sys::HtmlCanvasElement,
 }
 
 impl SurfaceGuard {
     fn check_for_unreported_errors(&self) -> bool {
         cfg_if::cfg_if! {
-            if #[cfg(all(target_arch = "wasm32", feature = "webgl"))] {
+            if #[cfg(all(target_arch = "wasm32", any(target_os = "emscripten", feature = "webgl")))] {
                 use wasm_bindgen::JsCast;
 
                 self.canvas
@@ -396,14 +405,20 @@ impl SurfaceGuard {
     }
 }
 
-#[cfg(all(target_arch = "wasm32", feature = "webgl"))]
+#[cfg(all(
+    target_arch = "wasm32",
+    any(target_os = "emscripten", feature = "webgl")
+))]
 impl Drop for SurfaceGuard {
     fn drop(&mut self) {
         delete_html_canvas();
     }
 }
 
-#[cfg(all(target_arch = "wasm32", feature = "webgl"))]
+#[cfg(all(
+    target_arch = "wasm32",
+    any(target_os = "emscripten", feature = "webgl")
+))]
 fn create_html_canvas() -> web_sys::HtmlCanvasElement {
     use wasm_bindgen::JsCast;
 
@@ -419,7 +434,10 @@ fn create_html_canvas() -> web_sys::HtmlCanvasElement {
         .expect("couldn't append canvas to document body")
 }
 
-#[cfg(all(target_arch = "wasm32", feature = "webgl"))]
+#[cfg(all(
+    target_arch = "wasm32",
+    any(target_os = "emscripten", feature = "webgl")
+))]
 fn delete_html_canvas() {
     if let Some(document) = web_sys::window().and_then(|win| win.document()) {
         if let Some(element) = document.get_element_by_id(CANVAS_ID) {
diff --git a/wgpu/tests/external_texture.rs b/wgpu/tests/external_texture.rs
index 49640a5174..2bb2ec21bb 100644
--- a/wgpu/tests/external_texture.rs
+++ b/wgpu/tests/external_texture.rs
@@ -1,4 +1,4 @@
-#![cfg(all(target_arch = "wasm32", not(features = "emscripten")))]
+#![cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
 
 use std::num::NonZeroU32;
 

From b918551c6f12694d0dc8e1db4dbf5171cca8cde3 Mon Sep 17 00:00:00 2001
From: dAxpeDDa <daxpedda@gmail.com>
Date: Wed, 15 Feb 2023 12:24:03 +0100
Subject: [PATCH 2/4] Address review

---
 wgpu/src/backend/direct.rs | 5 -----
 wgpu/src/backend/web.rs    | 1 -
 2 files changed, 6 deletions(-)

diff --git a/wgpu/src/backend/direct.rs b/wgpu/src/backend/direct.rs
index c4cc638f2d..b8d496d53f 100644
--- a/wgpu/src/backend/direct.rs
+++ b/wgpu/src/backend/direct.rs
@@ -128,11 +128,6 @@ impl Context {
         Ok((device, queue))
     }
 
-    #[cfg(any(
-        not(target_arch = "wasm32"),
-        target_os = "emscripten",
-        feature = "webgl"
-    ))]
     pub unsafe fn create_texture_from_hal<A: wgc::hub::HalApi>(
         &self,
         hal_texture: A::Texture,
diff --git a/wgpu/src/backend/web.rs b/wgpu/src/backend/web.rs
index 1b87355eaf..5017ddbcd0 100644
--- a/wgpu/src/backend/web.rs
+++ b/wgpu/src/backend/web.rs
@@ -2394,7 +2394,6 @@ impl crate::context::Context for Context {
             );
     }
 
-    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
     fn queue_copy_external_image_to_texture(
         &self,
         queue: &Self::QueueId,

From 054822e2ef7d857e3c28bda54d1bc842e8e6159f Mon Sep 17 00:00:00 2001
From: dAxpeDDa <daxpedda@gmail.com>
Date: Fri, 10 Feb 2023 12:05:21 +0100
Subject: [PATCH 3/4] Make crate features no-op on incompatible targets

---
 wgpu-core/src/device/mod.rs |  8 ++--
 wgpu-core/src/hub.rs        | 48 ++++++++++-----------
 wgpu-core/src/instance.rs   | 84 ++++++++++++++++++-------------------
 wgpu-core/src/lib.rs        | 16 +++----
 wgpu-hal/Cargo.toml         | 32 +++++++-------
 wgpu-hal/src/auxil/mod.rs   |  2 +-
 wgpu-hal/src/lib.rs         | 26 +++---------
 7 files changed, 101 insertions(+), 115 deletions(-)

diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index 49e158c664..17c0ef88cf 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -5530,22 +5530,22 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let mut closures = UserClosures::default();
         let mut all_queue_empty = true;
 
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         {
             all_queue_empty = self.poll_devices::<hal::api::Vulkan>(force_wait, &mut closures)?
                 && all_queue_empty;
         }
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         {
             all_queue_empty =
                 self.poll_devices::<hal::api::Metal>(force_wait, &mut closures)? && all_queue_empty;
         }
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         {
             all_queue_empty =
                 self.poll_devices::<hal::api::Dx12>(force_wait, &mut closures)? && all_queue_empty;
         }
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         {
             all_queue_empty =
                 self.poll_devices::<hal::api::Dx11>(force_wait, &mut closures)? && all_queue_empty;
diff --git a/wgpu-core/src/hub.rs b/wgpu-core/src/hub.rs
index e1b2f2557e..655a47ad18 100644
--- a/wgpu-core/src/hub.rs
+++ b/wgpu-core/src/hub.rs
@@ -1057,13 +1057,13 @@ impl<A: HalApi, F: GlobalIdentityHandlerFactory> Hub<A, F> {
 }
 
 pub struct Hubs<F: GlobalIdentityHandlerFactory> {
-    #[cfg(feature = "vulkan")]
+    #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
     vulkan: Hub<hal::api::Vulkan, F>,
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     metal: Hub<hal::api::Metal, F>,
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     dx12: Hub<hal::api::Dx12, F>,
-    #[cfg(feature = "dx11")]
+    #[cfg(all(feature = "dx11", windows))]
     dx11: Hub<hal::api::Dx11, F>,
     #[cfg(feature = "gles")]
     gl: Hub<hal::api::Gles, F>,
@@ -1072,13 +1072,13 @@ pub struct Hubs<F: GlobalIdentityHandlerFactory> {
 impl<F: GlobalIdentityHandlerFactory> Hubs<F> {
     fn new(factory: &F) -> Self {
         Self {
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: Hub::new(factory),
-            #[cfg(feature = "metal")]
+            #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
             metal: Hub::new(factory),
-            #[cfg(feature = "dx12")]
+            #[cfg(all(feature = "dx12", windows))]
             dx12: Hub::new(factory),
-            #[cfg(feature = "dx11")]
+            #[cfg(all(feature = "dx11", windows))]
             dx11: Hub::new(factory),
             #[cfg(feature = "gles")]
             gl: Hub::new(factory),
@@ -1089,13 +1089,13 @@ impl<F: GlobalIdentityHandlerFactory> Hubs<F> {
 #[derive(Debug)]
 pub struct GlobalReport {
     pub surfaces: StorageReport,
-    #[cfg(feature = "vulkan")]
+    #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
     pub vulkan: Option<HubReport>,
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     pub metal: Option<HubReport>,
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     pub dx12: Option<HubReport>,
-    #[cfg(feature = "dx11")]
+    #[cfg(all(feature = "dx11", windows))]
     pub dx11: Option<HubReport>,
     #[cfg(feature = "gles")]
     pub gl: Option<HubReport>,
@@ -1162,25 +1162,25 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
     pub fn generate_report(&self) -> GlobalReport {
         GlobalReport {
             surfaces: self.surfaces.data.read().generate_report(),
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: if self.instance.vulkan.is_some() {
                 Some(self.hubs.vulkan.generate_report())
             } else {
                 None
             },
-            #[cfg(feature = "metal")]
+            #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
             metal: if self.instance.metal.is_some() {
                 Some(self.hubs.metal.generate_report())
             } else {
                 None
             },
-            #[cfg(feature = "dx12")]
+            #[cfg(all(feature = "dx12", windows))]
             dx12: if self.instance.dx12.is_some() {
                 Some(self.hubs.dx12.generate_report())
             } else {
                 None
             },
-            #[cfg(feature = "dx11")]
+            #[cfg(all(feature = "dx11", windows))]
             dx11: if self.instance.dx11.is_some() {
                 Some(self.hubs.dx11.generate_report())
             } else {
@@ -1203,19 +1203,19 @@ impl<G: GlobalIdentityHandlerFactory> Drop for Global<G> {
         let mut surface_guard = self.surfaces.data.write();
 
         // destroy hubs before the instance gets dropped
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         {
             self.hubs.vulkan.clear(&mut surface_guard, true);
         }
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         {
             self.hubs.metal.clear(&mut surface_guard, true);
         }
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         {
             self.hubs.dx12.clear(&mut surface_guard, true);
         }
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         {
             self.hubs.dx11.clear(&mut surface_guard, true);
         }
@@ -1261,7 +1261,7 @@ impl HalApi for hal::api::Empty {
     }
 }
 
-#[cfg(feature = "vulkan")]
+#[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
 impl HalApi for hal::api::Vulkan {
     const VARIANT: Backend = Backend::Vulkan;
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance {
@@ -1285,7 +1285,7 @@ impl HalApi for hal::api::Vulkan {
     }
 }
 
-#[cfg(feature = "metal")]
+#[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
 impl HalApi for hal::api::Metal {
     const VARIANT: Backend = Backend::Metal;
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance {
@@ -1309,7 +1309,7 @@ impl HalApi for hal::api::Metal {
     }
 }
 
-#[cfg(feature = "dx12")]
+#[cfg(all(feature = "dx12", windows))]
 impl HalApi for hal::api::Dx12 {
     const VARIANT: Backend = Backend::Dx12;
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance {
@@ -1333,7 +1333,7 @@ impl HalApi for hal::api::Dx12 {
     }
 }
 
-#[cfg(feature = "dx11")]
+#[cfg(all(feature = "dx11", windows))]
 impl HalApi for hal::api::Dx11 {
     const VARIANT: Backend = Backend::Dx11;
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance {
diff --git a/wgpu-core/src/instance.rs b/wgpu-core/src/instance.rs
index 02e4b51885..5562312927 100644
--- a/wgpu-core/src/instance.rs
+++ b/wgpu-core/src/instance.rs
@@ -54,13 +54,13 @@ fn downlevel_default_limits_less_than_default_limits() {
 pub struct Instance {
     #[allow(dead_code)]
     pub name: String,
-    #[cfg(feature = "vulkan")]
+    #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
     pub vulkan: Option<HalInstance<hal::api::Vulkan>>,
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     pub metal: Option<HalInstance<hal::api::Metal>>,
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     pub dx12: Option<HalInstance<hal::api::Dx12>>,
-    #[cfg(feature = "dx11")]
+    #[cfg(all(feature = "dx11", windows))]
     pub dx11: Option<HalInstance<hal::api::Dx11>>,
     #[cfg(feature = "gles")]
     pub gl: Option<HalInstance<hal::api::Gles>>,
@@ -88,13 +88,13 @@ impl Instance {
 
         Self {
             name: name.to_string(),
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: init(hal::api::Vulkan, &instance_desc),
-            #[cfg(feature = "metal")]
+            #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
             metal: init(hal::api::Metal, &instance_desc),
-            #[cfg(feature = "dx12")]
+            #[cfg(all(feature = "dx12", windows))]
             dx12: init(hal::api::Dx12, &instance_desc),
-            #[cfg(feature = "dx11")]
+            #[cfg(all(feature = "dx11", windows))]
             dx11: init(hal::api::Dx11, &instance_desc),
             #[cfg(feature = "gles")]
             gl: init(hal::api::Gles, &instance_desc),
@@ -113,13 +113,13 @@ impl Instance {
                 }
             }
         }
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         destroy(hal::api::Vulkan, &self.vulkan, surface.vulkan);
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         destroy(hal::api::Metal, &self.metal, surface.metal);
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         destroy(hal::api::Dx12, &self.dx12, surface.dx12);
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         destroy(hal::api::Dx11, &self.dx11, surface.dx11);
         #[cfg(feature = "gles")]
         destroy(hal::api::Gles, &self.gl, surface.gl);
@@ -128,13 +128,13 @@ impl Instance {
 
 pub struct Surface {
     pub(crate) presentation: Option<Presentation>,
-    #[cfg(feature = "vulkan")]
+    #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
     pub vulkan: Option<HalSurface<hal::api::Vulkan>>,
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     pub metal: Option<HalSurface<hal::api::Metal>>,
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     pub dx12: Option<HalSurface<hal::api::Dx12>>,
-    #[cfg(feature = "dx11")]
+    #[cfg(all(feature = "dx11", windows))]
     pub dx11: Option<HalSurface<hal::api::Dx11>>,
     #[cfg(feature = "gles")]
     pub gl: Option<HalSurface<hal::api::Gles>>,
@@ -468,13 +468,13 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let surface = Surface {
             presentation: None,
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: init::<hal::api::Vulkan>(&self.instance.vulkan, display_handle, window_handle),
-            #[cfg(feature = "metal")]
+            #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
             metal: init::<hal::api::Metal>(&self.instance.metal, display_handle, window_handle),
-            #[cfg(feature = "dx12")]
+            #[cfg(all(feature = "dx12", windows))]
             dx12: init::<hal::api::Dx12>(&self.instance.dx12, display_handle, window_handle),
-            #[cfg(feature = "dx11")]
+            #[cfg(all(feature = "dx11", windows))]
             dx11: init::<hal::api::Dx11>(&self.instance.dx11, display_handle, window_handle),
             #[cfg(feature = "gles")]
             gl: init::<hal::api::Gles>(&self.instance.gl, display_handle, window_handle),
@@ -485,7 +485,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         id.0
     }
 
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     pub fn instance_create_surface_metal(
         &self,
         layer: *mut std::ffi::c_void,
@@ -503,7 +503,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                 },
                 //acquired_texture: None,
             }),
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: None,
             #[cfg(feature = "gles")]
             gl: None,
@@ -568,7 +568,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         Ok(id.0)
     }
 
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     /// # Safety
     ///
     /// The visual must be valid and able to be used to make a swapchain with.
@@ -581,7 +581,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let surface = Surface {
             presentation: None,
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: None,
             dx12: self.instance.dx12.as_ref().map(|inst| HalSurface {
                 raw: unsafe { inst.create_surface_from_visual(visual as _) },
@@ -596,7 +596,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         id.0
     }
 
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     /// # Safety
     ///
     /// The surface_handle must be valid and able to be used to make a swapchain with.
@@ -609,7 +609,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let surface = Surface {
             presentation: None,
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             vulkan: None,
             dx12: self.instance.dx12.as_ref().map(|inst| HalSurface {
                 raw: unsafe { inst.create_surface_from_surface_handle(surface_handle) },
@@ -668,23 +668,23 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let mut adapters = Vec::new();
 
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         self.enumerate(
             hal::api::Vulkan,
             &self.instance.vulkan,
             &inputs,
             &mut adapters,
         );
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         self.enumerate(
             hal::api::Metal,
             &self.instance.metal,
             &inputs,
             &mut adapters,
         );
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         self.enumerate(hal::api::Dx12, &self.instance.dx12, &inputs, &mut adapters);
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         self.enumerate(hal::api::Dx11, &self.instance.dx11, &inputs, &mut adapters);
         #[cfg(feature = "gles")]
         self.enumerate(hal::api::Gles, &self.instance.gl, &inputs, &mut adapters);
@@ -769,7 +769,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .transpose()?;
         let mut device_types = Vec::new();
 
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         let (id_vulkan, adapters_vk) = gather(
             hal::api::Vulkan,
             self.instance.vulkan.as_ref(),
@@ -778,7 +778,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             desc.force_fallback_adapter,
             &mut device_types,
         );
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         let (id_metal, adapters_metal) = gather(
             hal::api::Metal,
             self.instance.metal.as_ref(),
@@ -787,7 +787,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             desc.force_fallback_adapter,
             &mut device_types,
         );
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         let (id_dx12, adapters_dx12) = gather(
             hal::api::Dx12,
             self.instance.dx12.as_ref(),
@@ -796,7 +796,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             desc.force_fallback_adapter,
             &mut device_types,
         );
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         let (id_dx11, adapters_dx11) = gather(
             hal::api::Dx11,
             self.instance.dx11.as_ref(),
@@ -858,19 +858,19 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         };
 
         let mut selected = preferred_gpu.unwrap_or(0);
-        #[cfg(feature = "vulkan")]
+        #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
         if let Some(id) = self.select(&mut selected, id_vulkan, adapters_vk) {
             return Ok(id);
         }
-        #[cfg(feature = "metal")]
+        #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
         if let Some(id) = self.select(&mut selected, id_metal, adapters_metal) {
             return Ok(id);
         }
-        #[cfg(feature = "dx12")]
+        #[cfg(all(feature = "dx12", windows))]
         if let Some(id) = self.select(&mut selected, id_dx12, adapters_dx12) {
             return Ok(id);
         }
-        #[cfg(feature = "dx11")]
+        #[cfg(all(feature = "dx11", windows))]
         if let Some(id) = self.select(&mut selected, id_dx11, adapters_dx11) {
             return Ok(id);
         }
@@ -898,13 +898,13 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let fid = A::hub(self).adapters.prepare(input);
 
         match A::VARIANT {
-            #[cfg(feature = "vulkan")]
+            #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
             Backend::Vulkan => fid.assign(Adapter::new(hal_adapter), &mut token).0,
-            #[cfg(feature = "metal")]
+            #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
             Backend::Metal => fid.assign(Adapter::new(hal_adapter), &mut token).0,
-            #[cfg(feature = "dx12")]
+            #[cfg(all(feature = "dx12", windows))]
             Backend::Dx12 => fid.assign(Adapter::new(hal_adapter), &mut token).0,
-            #[cfg(feature = "dx11")]
+            #[cfg(all(feature = "dx11", windows))]
             Backend::Dx11 => fid.assign(Adapter::new(hal_adapter), &mut token).0,
             #[cfg(feature = "gles")]
             Backend::Gl => fid.assign(Adapter::new(hal_adapter), &mut token).0,
diff --git a/wgpu-core/src/lib.rs b/wgpu-core/src/lib.rs
index 041cb2ef0b..dcd283e268 100644
--- a/wgpu-core/src/lib.rs
+++ b/wgpu-core/src/lib.rs
@@ -295,14 +295,14 @@ platform supports.";
 /// private name, which is never used outside this macro. For details:
 /// <https://github.com/rust-lang/rust/pull/52234#issuecomment-976702997>
 macro_rules! define_backend_caller {
-    { $public:ident, $private:ident if $feature:literal } => {
-        #[cfg(feature = $feature )]
+    { $public:ident, $private:ident, $feature:literal if $cfg:meta } => {
+        #[cfg($cfg)]
         #[macro_export]
         macro_rules! $private {
             ( $call:expr ) => ( $call )
         }
 
-        #[cfg(not(feature = $feature ))]
+        #[cfg(not($cfg))]
         #[macro_export]
         macro_rules! $private {
             ( $call:expr ) => (
@@ -321,11 +321,11 @@ macro_rules! define_backend_caller {
 //
 // expands to `expr` if the `"vulkan"` feature is enabled, or to a panic
 // otherwise.
-define_backend_caller! { gfx_if_vulkan, gfx_if_vulkan_hidden if "vulkan" }
-define_backend_caller! { gfx_if_metal, gfx_if_metal_hidden if "metal" }
-define_backend_caller! { gfx_if_dx12, gfx_if_dx12_hidden if "dx12" }
-define_backend_caller! { gfx_if_dx11, gfx_if_dx11_hidden if "dx11" }
-define_backend_caller! { gfx_if_gles, gfx_if_gles_hidden if "gles" }
+define_backend_caller! { gfx_if_vulkan, gfx_if_vulkan_hidden, "vulkan" if all(feature = "vulkan", not(target_arch = "wasm32")) }
+define_backend_caller! { gfx_if_metal, gfx_if_metal_hidden, "metal" if all(feature = "metal", any(target_os = "macos", target_os = "ios")) }
+define_backend_caller! { gfx_if_dx12, gfx_if_dx12_hidden, "dx12" if all(feature = "dx12", windows) }
+define_backend_caller! { gfx_if_dx11, gfx_if_dx11_hidden, "dx11" if all(feature = "dx11", windows) }
+define_backend_caller! { gfx_if_gles, gfx_if_gles_hidden, "gles" if feature = "gles" }
 
 /// Dispatch on an [`Id`]'s backend to a backend-generic method.
 ///
diff --git a/wgpu-hal/Cargo.toml b/wgpu-hal/Cargo.toml
index e198ab7e8f..faa17a4aa1 100644
--- a/wgpu-hal/Cargo.toml
+++ b/wgpu-hal/Cargo.toml
@@ -64,31 +64,21 @@ fxhash = "0.2.1"
 log = "0.4"
 renderdoc-sys = { version = "0.7.1", optional = true }
 
-# backend: Metal
-block = { version = "0.1", optional = true }
-foreign-types = { version = "0.3", optional = true }
-
-# backend: Vulkan
-ash = { version = "0.37.2", optional = true }
-gpu-alloc = { version = "0.5", optional = true }
-gpu-descriptor = { version = "0.2", optional = true }
-smallvec = { version = "1", optional = true, features = ["union"] }
-
 # backend: Gles
 glow = { version = "0.12.0", optional = true }
 
-# backend: Dx12
-bit-set = { version = "0.5", optional = true }
-range-alloc = { version = "0.1", optional = true }
-gpu-allocator = { version = "0.22", default_features = false, features = ["d3d12", "windows", "public-winapi"], optional = true }
-hassle-rs = { version = "0.10", optional = true }
-
 [dependencies.wgt]
 package = "wgpu-types"
 path = "../wgpu-types"
 version = "0.15"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+# backend: Vulkan
+ash = { version = "0.37.2", optional = true }
+gpu-alloc = { version = "0.5", optional = true }
+gpu-descriptor = { version = "0.2", optional = true }
+smallvec = { version = "1", optional = true, features = ["union"] }
+
 egl = { package = "khronos-egl", version = "4.1", features = ["dynamic"], optional = true }
 libloading = { version = "0.7", optional = true }
 
@@ -98,10 +88,20 @@ egl = { package = "khronos-egl", version = "4.1", features = ["static", "no-pkg-
 libloading = { version = "0.7", optional = true }
 
 [target.'cfg(windows)'.dependencies]
+# backend: Dx12
+bit-set = { version = "0.5", optional = true }
+range-alloc = { version = "0.1", optional = true }
+gpu-allocator = { version = "0.22", default_features = false, features = ["d3d12", "windows", "public-winapi"], optional = true }
+hassle-rs = { version = "0.10", optional = true }
+
 winapi = { version = "0.3", features = ["profileapi", "libloaderapi", "windef", "winuser", "dcomp"] }
 native = { package = "d3d12", version = "0.6.0", git = "https://github.com/gfx-rs/d3d12-rs", rev = "b940b1d71", features = ["libloading"], optional = true }
 
 [target.'cfg(any(target_os="macos", target_os="ios"))'.dependencies]
+# backend: Metal
+block = { version = "0.1", optional = true }
+foreign-types = { version = "0.3", optional = true }
+
 mtl = { package = "metal", version = "0.24.0" }
 objc = "0.2.5"
 core-graphics-types = "0.1"
diff --git a/wgpu-hal/src/auxil/mod.rs b/wgpu-hal/src/auxil/mod.rs
index b496692bea..da7dbac668 100644
--- a/wgpu-hal/src/auxil/mod.rs
+++ b/wgpu-hal/src/auxil/mod.rs
@@ -1,4 +1,4 @@
-#[cfg(any(feature = "dx11", feature = "dx12"))]
+#[cfg(all(any(feature = "dx11", feature = "dx12"), windows))]
 pub(super) mod dxgi;
 
 #[cfg(feature = "renderdoc")]
diff --git a/wgpu-hal/src/lib.rs b/wgpu-hal/src/lib.rs
index 58c70e3ac1..a1484970db 100644
--- a/wgpu-hal/src/lib.rs
+++ b/wgpu-hal/src/lib.rs
@@ -51,20 +51,6 @@
     clippy::pattern_type_mismatch,
 )]
 
-#[cfg(not(any(
-    feature = "dx11",
-    feature = "dx12",
-    feature = "gles",
-    feature = "metal",
-    feature = "vulkan"
-)))]
-compile_error!("No back ends enabled in `wgpu-hal`. Enable at least one backend feature.");
-
-#[cfg(all(feature = "metal", not(any(target_os = "macos", target_os = "ios"))))]
-compile_error!("Metal API enabled on non-Apple OS. If your project is not using resolver=\"2\" in Cargo.toml, it should.");
-#[cfg(all(feature = "dx12", not(windows)))]
-compile_error!("DX12 API enabled on non-Windows OS. If your project is not using resolver=\"2\" in Cargo.toml, it should.");
-
 /// DirectX11 API internals.
 #[cfg(all(feature = "dx11", windows))]
 pub mod dx11;
@@ -77,24 +63,24 @@ pub mod empty;
 #[cfg(all(feature = "gles"))]
 pub mod gles;
 /// Metal API internals.
-#[cfg(all(feature = "metal"))]
+#[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
 pub mod metal;
 /// Vulkan API internals.
-#[cfg(feature = "vulkan")]
+#[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
 pub mod vulkan;
 
 pub mod auxil;
 pub mod api {
-    #[cfg(feature = "dx11")]
+    #[cfg(all(feature = "dx11", windows))]
     pub use super::dx11::Api as Dx11;
-    #[cfg(feature = "dx12")]
+    #[cfg(all(feature = "dx12", windows))]
     pub use super::dx12::Api as Dx12;
     pub use super::empty::Api as Empty;
     #[cfg(feature = "gles")]
     pub use super::gles::Api as Gles;
-    #[cfg(feature = "metal")]
+    #[cfg(all(feature = "metal", any(target_os = "macos", target_os = "ios")))]
     pub use super::metal::Api as Metal;
-    #[cfg(feature = "vulkan")]
+    #[cfg(all(feature = "vulkan", not(target_arch = "wasm32")))]
     pub use super::vulkan::Api as Vulkan;
 }
 

From 03f303b391ffe59a3299687766caed2da62102a4 Mon Sep 17 00:00:00 2001
From: dAxpeDDa <daxpedda@gmail.com>
Date: Wed, 15 Feb 2023 12:02:48 +0100
Subject: [PATCH 4/4] Remove `portable_features`

---
 .github/workflows/ci.yml | 4 ++--
 wgpu-core/Cargo.toml     | 3 ---
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c95c31ad90..0ebe40fb7b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -160,13 +160,13 @@ jobs:
           # (But watch out for backend-selection features in wgpu-core; some of
           # those only build on the right platforms.)
           cargo clippy --target ${{ matrix.target }} -p wgpu -p wgpu-info -p player --tests --all-features
-          cargo clippy --target ${{ matrix.target }} -p wgpu-core --tests --features="portable_features"
+          cargo clippy --target ${{ matrix.target }} -p wgpu-core --tests --all-features
 
           # build docs
           # (Watch out for backend-selection features in wgpu-core; some of
           # those only build on the right platforms.)
           cargo doc --target ${{ matrix.target }} -p wgpu -p wgpu-info -p player --all-features --no-deps
-          cargo doc --target ${{ matrix.target }} -p wgpu-core --no-deps --features="portable_features"
+          cargo doc --target ${{ matrix.target }} -p wgpu-core --no-deps --all-features
 
   wasm-test:
     name: Test WebAssembly
diff --git a/wgpu-core/Cargo.toml b/wgpu-core/Cargo.toml
index 95a8133d11..b45f40c856 100644
--- a/wgpu-core/Cargo.toml
+++ b/wgpu-core/Cargo.toml
@@ -49,9 +49,6 @@ id32 = []
 # Enable `ShaderModuleSource::Wgsl`
 wgsl = ["naga/wgsl-in"]
 
-# Features that are intended to work on all platforms.
-portable_features = ["gles", "strict_asserts", "trace", "replay", "serial-pass", "id32", "wgsl"]
-
 [dependencies]
 arrayvec = "0.7"
 bitflags = "1"