Condition macro_rules_attribute dev-dependency on serde feature

Author: andyleiserson

wgpu-core/Cargo.toml

@@ -69,7 +69,14 @@ observe_locks = ["std", "dep:ron", "serde/serde_derive"]
 # --------------------------------------------------------------------
 
 ## Enables serialization via `serde` on common wgpu types.
-serde = ["dep:serde", "wgpu-types/serde", "arrayvec/serde", "hashbrown/serde", "smallvec/serde"]
+serde = [
+    "dep:serde",
+    "wgpu-types/serde",
+    "arrayvec/serde",
+    "hashbrown/serde",
+    "smallvec/serde",
+    "macro_rules_attribute",
+]
 
 ## Enable API tracing.
 trace = ["serde", "std", "dep:ron", "naga/serialize", "wgpu-types/trace"]
@@ -178,7 +185,7 @@ document-features.workspace = true
 hashbrown.workspace = true
 indexmap.workspace = true
 log.workspace = true
-macro_rules_attribute.workspace = true
+macro_rules_attribute = { workspace = true, optional = true }
 once_cell = { workspace = true, features = ["std"] }
 parking_lot.workspace = true
 profiling = { workspace = true, default-features = false }

wgpu-core/src/command/compute_command.rs

@@ -1,5 +1,6 @@
 use crate::command::{serde_object_reference_struct, ArcReferences, ReferenceType};
 
+#[cfg(feature = "serde")]
 use macro_rules_attribute::apply;
 
 /// cbindgen:ignore

wgpu-core/src/command/render_command.rs

@@ -3,6 +3,7 @@ use wgt::{BufferAddress, BufferSize, Color};
 use super::{DrawCommandFamily, Rect};
 use crate::command::{serde_object_reference_struct, ArcReferences, ReferenceType};
 
+#[cfg(feature = "serde")]
 use macro_rules_attribute::apply;
 
 /// cbindgen:ignore

wgpu-core/src/ray_tracing.rs

@@ -10,6 +10,7 @@
 
 use alloc::{boxed::Box, sync::Arc, vec::Vec};
 
+#[cfg(feature = "serde")]
 use macro_rules_attribute::apply;
 use thiserror::Error;
 use wgt::{