feat(syntax): derive CloneIn for the AST-related items. (#4730)

Follow-on after #4276, related to #4284.

Cargo.lock

@@ -1769,6 +1769,7 @@ dependencies = [
  "bitflags 2.6.0",
  "dashmap 6.0.1",
  "nonmax",
+ "oxc_allocator",
  "oxc_ast_macros",
  "oxc_index",
  "oxc_span",

crates/oxc_ast_macros/src/lib.rs

@@ -53,3 +53,32 @@ pub fn ast(_args: TokenStream, input: TokenStream) -> TokenStream {
 pub fn ast_derive(_item: TokenStream) -> TokenStream {
     TokenStream::new()
 }
+
+/// Derive macro generating an impl of the trait `CloneIn`.
+///
+/// NOTE: This is an internal macro!
+/// # Panics
+///
+#[proc_macro_derive(CloneIn)]
+pub fn derive_clone_in(item: TokenStream) -> TokenStream {
+    let item = syn::parse_macro_input!(item as syn::Item);
+    match &item {
+        syn::Item::Struct(syn::ItemStruct { ident, generics, .. })
+        | syn::Item::Enum(syn::ItemEnum { ident, generics, .. })
+            if generics.params.is_empty() =>
+        {
+            quote! {
+                #[automatically_derived]
+                impl<'alloc> ::oxc_allocator::CloneIn<'alloc> for #ident {
+                    type Cloned = #ident;
+
+                    fn clone_in(&self, _: &'alloc ::oxc_allocator::Allocator) -> Self::Cloned {
+                        std::clone::Clone::clone(self)
+                    }
+                }
+            }
+            .into()
+        }
+        _ => panic!("At the moment `CloneIn` derive macro only works for types without lifetimes and/or generic params"),
+    }
+}

crates/oxc_syntax/Cargo.toml

@@ -23,6 +23,7 @@ doctest = false
 oxc_index      = { workspace = true }
 oxc_span       = { workspace = true }
 oxc_ast_macros = { workspace = true }
+oxc_allocator  = { workspace = true }
 
 unicode-id-start = { workspace = true }
 bitflags         = { workspace = true }
@@ -40,3 +41,9 @@ wasm-bindgen = { workspace = true, optional = true }
 default      = []
 to_js_string = ["dep:ryu-js"]
 serialize    = ["bitflags/serde", "dep:serde", "dep:tsify", "dep:wasm-bindgen", "oxc_index/serialize"]
+
+[package.metadata.cargo-shear]
+# We use `oxc_ast_macros::CloneIn` which expands to use `oxc_allocator`.
+# To fix this we have to expose `CloneIn` through `oxc_allocator`
+# (and probably move it to `oxc_allocator_derive`).
+ignored = ["oxc_allocator"]

crates/oxc_syntax/src/number.rs

@@ -1,7 +1,7 @@
-use oxc_ast_macros::ast;
+use oxc_ast_macros::{ast, CloneIn};
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 pub enum NumberBase {
     Float = 0,
     Decimal = 1,
@@ -17,7 +17,7 @@ impl NumberBase {
 }
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 pub enum BigintBase {
     Decimal = 0,
     Binary = 1,

crates/oxc_syntax/src/operator.rs

@@ -4,12 +4,12 @@
 #[cfg(feature = "serialize")]
 use ::{serde::Serialize, tsify::Tsify};
 
-use oxc_ast_macros::ast;
+use oxc_ast_macros::{ast, CloneIn};
 
 use crate::precedence::{GetPrecedence, Precedence};
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]
 pub enum AssignmentOperator {
     #[serde(rename = "=")]
@@ -88,7 +88,7 @@ impl AssignmentOperator {
 }
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]
 pub enum BinaryOperator {
     #[serde(rename = "==")]
@@ -276,7 +276,7 @@ impl GetPrecedence for BinaryOperator {
 }
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]
 pub enum LogicalOperator {
     #[serde(rename = "||")]
@@ -316,7 +316,7 @@ impl GetPrecedence for LogicalOperator {
 }
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]
 pub enum UnaryOperator {
     #[serde(rename = "-")]
@@ -369,7 +369,7 @@ impl UnaryOperator {
 }
 
 #[ast]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, CloneIn)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]
 pub enum UpdateOperator {
     #[serde(rename = "++")]

crates/oxc_syntax/src/reference.rs

@@ -1,5 +1,6 @@
 use bitflags::bitflags;
 use nonmax::NonMaxU32;
+use oxc_ast_macros::CloneIn;
 #[cfg(feature = "serialize")]
 use serde::{Serialize, Serializer};
 
@@ -45,7 +46,7 @@ export type ReferenceFlag = {
 "#;
 
 bitflags! {
-    #[derive(Debug, Default, Clone, Copy, Eq, PartialEq)]
+    #[derive(Debug, Default, Clone, Copy, Eq, PartialEq, CloneIn)]
     #[cfg_attr(feature = "serialize", derive(Serialize))]
     pub struct ReferenceFlag: u8 {
         const None = 0;