Add Fold and VisitMut methods for Vec<Attribute>

Author: dtolnay

codegen/src/fold.rs

@@ -1,3 +1,4 @@
+use crate::cfg::{self, DocCfg};
 use crate::{file, full, gen};
 use anyhow::Result;
 use proc_macro2::{Ident, Span, TokenStream};
@@ -32,10 +33,16 @@ fn visit(
         }
         Type::Vec(t) => {
             let Type::Syn(t) = &**t else { unimplemented!() };
-            let method = method_name(t);
-            Some(quote! {
-                fold_vec(#name, f, F::#method)
-            })
+            if t == "Attribute" {
+                Some(quote! {
+                    f.fold_attributes(#name)
+                })
+            } else {
+                let method = method_name(t);
+                Some(quote! {
+                    fold_vec(#name, f, F::#method)
+                })
+            }
         }
         Type::Punctuated(p) => {
             let t = &*p.element;
@@ -214,6 +221,16 @@ fn node(traits: &mut TokenStream, impls: &mut TokenStream, s: &Node, defs: &Defi
             #fold_impl
         }
     });
+
+    if s.ident == "Attribute" {
+        let features = cfg::features(&s.features, DocCfg::Ordinary);
+        traits.extend(quote! {
+            #features
+            fn fold_attributes(&mut self, i: Vec<crate::Attribute>) -> Vec<crate::Attribute> {
+                fold_vec(i, self, Self::fold_attribute)
+            }
+        });
+    }
 }
 
 pub fn generate(defs: &Definitions) -> Result<()> {

codegen/src/visit_mut.rs

@@ -1,3 +1,4 @@
+use crate::cfg::{self, DocCfg};
 use crate::operand::{Borrowed, Operand, Owned};
 use crate::{file, full, gen};
 use anyhow::Result;
@@ -36,14 +37,20 @@ fn visit(
             visit(t, features, defs, &Owned(quote!(*#name)))
         }
         Type::Vec(t) => {
-            let operand = Borrowed(quote!(it));
-            let val = visit(t, features, defs, &operand)?;
             let name = name.ref_mut_tokens();
-            Some(quote! {
-                for it in #name {
-                    #val;
-                }
-            })
+            if matches!(&**t, Type::Syn(t) if t == "Attribute") {
+                Some(quote! {
+                    v.visit_attributes_mut(#name);
+                })
+            } else {
+                let operand = Borrowed(quote!(it));
+                let val = visit(t, features, defs, &operand)?;
+                Some(quote! {
+                    for it in #name {
+                        #val;
+                    }
+                })
+            }
         }
         Type::Punctuated(p) => {
             let operand = Borrowed(quote!(it));
@@ -193,6 +200,18 @@ fn node(traits: &mut TokenStream, impls: &mut TokenStream, s: &Node, defs: &Defi
             #visit_mut_impl
         }
     });
+
+    if s.ident == "Attribute" {
+        let features = cfg::features(&s.features, DocCfg::Ordinary);
+        traits.extend(quote! {
+            #features
+            fn visit_attributes_mut(&mut self, i: &mut Vec<crate::Attribute>) {
+                for attr in i {
+                    self.visit_attribute_mut(attr);
+                }
+            }
+        });
+    }
 }
 
 pub fn generate(defs: &Definitions) -> Result<()> {