feat(turbo-tasks): Ignore fields annotated with `#[turbo_tasks(trace_…

…ignore)]` (#70375) This annotation implies that the field does not contain any `Vc` types, so we can re-use that here. We can skip checking for `ResolvedValue` on these fields. As we start codemodding stuff, we should consider renaming this annotation to something more generic (e.g. `#[turbo_tasks(does_not_contain_vc)]`), but this is good enough for now.
vercel · Sep 24, 2024 · 538b1c6 · 538b1c6
1 parent bd68cef
commit 538b1c6
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Showing 3 changed files with 32 additions and 10 deletions.
diff --git a/turbopack/crates/turbo-tasks-macros-tests/tests/derive_resolved_value/pass_ignore_field.rs b/turbopack/crates/turbo-tasks-macros-tests/tests/derive_resolved_value/pass_ignore_field.rs
@@ -0,0 +1,17 @@
+use std::marker::PhantomData;
+
+use turbo_tasks::ResolvedValue;
+
+struct UnannotatedValue<T>(PhantomData<T>);
+
+#[derive(ResolvedValue)]
+struct ContainsIgnore<T> {
+    #[turbo_tasks(trace_ignore)]
+    a: UnannotatedValue<T>,
+}
+
+fn main() {
+    let _ = ContainsIgnore {
+        a: UnannotatedValue(PhantomData::<u32>),
+    };
+}
diff --git a/turbopack/crates/turbo-tasks-macros/src/derive/resolved_value_macro.rs b/turbopack/crates/turbo-tasks-macros/src/derive/resolved_value_macro.rs
@@ -4,6 +4,8 @@ use proc_macro2::TokenStream as TokenStream2;
 use quote::{quote, quote_spanned};
 use syn::{parse_macro_input, spanned::Spanned, Data, DeriveInput, Generics};
 
+use crate::derive::trace_raw_vcs_macro::filter_field;
+
 pub fn derive_resolved_value(input: TokenStream) -> TokenStream {
     let derive_input = parse_macro_input!(input as DeriveInput);
     let ident = &derive_input.ident;
@@ -31,15 +33,18 @@ fn assert_fields_impl_resolved_value(generics: &Generics, data: &Data) -> TokenS
     // this technique is based on the trick used by
     // `static_assertions::assert_impl_all`, but extended to support generics.
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
-    let field_types: Vec<_> = iter_data_fields(data).map(|field| &field.ty).collect();
-    let assertion_calls = field_types.iter().map(|ty| {
-        quote_spanned! {
-            // attribute type assertion errors to the line where the field is defined
-            ty.span() =>
-            // this call is only valid if ty is a ResolvedValue
-            Self::assert_impl_resolved_value::<#ty>();
-        }
-    });
+    let field_types = iter_data_fields(data).map(|field| &field.ty);
+    let assertion_calls = iter_data_fields(data)
+        .filter(|field| filter_field(field))
+        .map(|field| {
+            let ty = &field.ty;
+            quote_spanned! {
+                // attribute type assertion errors to the line where the field is defined
+                ty.span() =>
+                // this call is only valid if ty is a ResolvedValue
+                Self::assert_impl_resolved_value::<#ty>();
+            }
+        });
     quote! {
         const _: fn() = || {
             // create this struct just to hold onto our generics...

diff --git a/turbopack/crates/turbo-tasks-macros/src/derive/trace_raw_vcs_macro.rs b/turbopack/crates/turbo-tasks-macros/src/derive/trace_raw_vcs_macro.rs
@@ -6,7 +6,7 @@ use turbo_tasks_macros_shared::{generate_destructuring, match_expansion};
 
 use super::FieldAttributes;
 
-fn filter_field(field: &Field) -> bool {
+pub fn filter_field(field: &Field) -> bool {
     !FieldAttributes::from(field.attrs.as_slice()).trace_ignore
 }