Allow unspecified bits in the API's bitflags

The bitflags_serde_shim treats unspecified bits as errors during deserialization. To make the browser integration easier, we want the unsepcified bits (which can be produced by web content) to turn into validation errors instead of panics during deserialization.

Thankfully the bitflags_serde_shim crate is quite trivial, so this PR inlines the macro with the required modification to not check the bits. In addition, bitflags_serde_shim feature is removed, the Serialize and Deserialize implementations are aways the same and only their presence depend on the trace and replay feature flags.

Cargo.toml

@@ -46,7 +46,6 @@ version = "0.10"
 arrayvec = "0.7"
 async-executor = "1.0"
 bitflags = "1"
-bitflags_serde_shim = "0.2"
 bit-vec = "0.6"
 bytemuck = "1.4"
 cargo-run-wasm = "0.2.0"

wgpu-types/Cargo.toml

@@ -16,13 +16,12 @@ rustdoc-args = ["--cfg", "docsrs"]
 [lib]
 
 [features]
-trace = ["serde", "bitflags_serde_shim"]
-replay = ["serde", "bitflags_serde_shim"]
+trace = ["serde"]
+replay = ["serde"]
 
 [dependencies]
 bitflags.workspace = true
 serde = { workspace = true, features = ["serde_derive"], optional = true }
-bitflags_serde_shim = { workspace = true, optional = true }
 
 [dev-dependencies]
 serde_json.workspace = true

wgpu-types/src/lib.rs

@@ -14,6 +14,37 @@ use serde::{Deserialize, Serialize};
 use std::hash::{Hash, Hasher};
 use std::{num::NonZeroU32, ops::Range};
 
+// Use this macro instead of the one provided by the bitflags_serde_shim crate
+// because the latter produces an error when deserializing bits that are not
+// specified in the bitflags, while we want deserialization to succeed and
+// and unspecified bits to lead to errors handled in wgpu-core.
+// Note that plainly deriving Serialize and Deserialized would have a similar
+// behavior to this macro (unspecified bit do not produce an error).
+macro_rules! impl_serde_for_bitflags {
+    ($name:ident) => {
+        #[cfg(feature = "trace")]
+        impl serde::Serialize for $name {
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: serde::Serializer,
+            {
+                self.bits().serialize(serializer)
+            }
+        }
+
+        #[cfg(feature = "replay")]
+        impl<'de> serde::Deserialize<'de> for $name {
+            fn deserialize<D>(deserializer: D) -> Result<$name, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                let value = <_ as serde::Deserialize<'de>>::deserialize(deserializer)?;
+                Ok(unsafe { $name::from_bits_unchecked(value) })
+            }
+        }
+    };
+}
+
 /// Integral type used for buffer offsets.
 pub type BufferAddress = u64;
 /// Integral type used for buffer slice sizes.
@@ -115,8 +146,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(Backends);
+impl_serde_for_bitflags!(Backends);
 
 impl From<Backend> for Backends {
     fn from(backend: Backend) -> Self {
@@ -633,8 +663,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(Features);
+impl_serde_for_bitflags!(Features);
 
 impl Features {
     /// Mask of all features which are part of the upstream WebGPU standard.
@@ -1090,8 +1119,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(DownlevelFlags);
+impl_serde_for_bitflags!(DownlevelFlags);
 
 impl DownlevelFlags {
     /// All flags that indicate if the backend is WebGPU compliant
@@ -1213,8 +1241,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(ShaderStages);
+impl_serde_for_bitflags!(ShaderStages);
 
 /// Dimensions of a particular texture view.
 ///
@@ -1666,8 +1693,7 @@ impl TextureFormatFeatureFlags {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(TextureFormatFeatureFlags);
+impl_serde_for_bitflags!(TextureFormatFeatureFlags);
 
 /// Features supported by a given texture format
 ///
@@ -3085,8 +3111,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(ColorWrites);
+impl_serde_for_bitflags!(ColorWrites);
 
 impl Default for ColorWrites {
     fn default() -> Self {
@@ -3644,8 +3669,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(BufferUsages);
+impl_serde_for_bitflags!(BufferUsages);
 
 /// Describes a [`Buffer`](../wgpu/struct.Buffer.html).
 ///
@@ -3846,8 +3870,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(TextureUsages);
+impl_serde_for_bitflags!(TextureUsages);
 
 /// Configures a [`Surface`] for presentation.
 ///
@@ -5046,8 +5069,7 @@ bitflags::bitflags! {
     }
 }
 
-#[cfg(feature = "bitflags_serde_shim")]
-bitflags_serde_shim::impl_serde_for_bitflags!(PipelineStatisticsTypes);
+impl_serde_for_bitflags!(PipelineStatisticsTypes);
 
 /// Argument buffer layout for draw_indirect commands.
 #[repr(C)]