Update to syn 2.0

Author: LukasKalbertodt

macro/Cargo.toml

@@ -12,7 +12,7 @@ license = "MIT/Apache-2.0"
 proc-macro = true
 
 [dependencies]
-syn = "1.0"
+syn = "2.0"
 quote = "1.0"
 proc-macro2 = "1.0"
 heck = "0.5.0"

macro/src/gen/mod.rs

@@ -419,7 +419,10 @@ fn default_value_to_deserializable_expr(expr: &ir::Expr) -> TokenStream {
 fn inner_visibility(outer: &syn::Visibility, span: Span) -> TokenStream {
     match outer {
         // These visibilities can be used as they are. No adjustment needed.
-        syn::Visibility::Public(_) | syn::Visibility::Crate(_) => quote_spanned! {span=> #outer },
+        syn::Visibility::Public(_) => quote_spanned! {span=> #outer },
+        syn::Visibility::Restricted(r) if r.path.is_ident("crate") && r.in_token.is_none() => {
+            quote_spanned! {span=> #outer }
+        },
 
         // The inherited one is relative to the parent module.
         syn::Visibility::Inherited => quote_spanned! {span=> pub(super) },

macro/src/parse.rs

@@ -64,7 +64,7 @@ impl StructAttrs {
                     ($cond:expr) => {
                         if $cond {
                             let msg = format!("duplicate '{keyword}' confique attribute");
-                            return Err(Error::new(attr.tokens.span(), msg));
+                            return Err(Error::new(attr.path().span(), msg));
                         }
                     };
                 }
@@ -214,7 +214,7 @@ impl FieldAttrs {
                     ($cond:expr) => {
                         if $cond {
                             let msg = format!("duplicate '{keyword}' confique attribute");
-                            return Err(Error::new(attr.tokens.span(), msg));
+                            return Err(Error::new(attr.path().span(), msg));
                         }
                     };
                 }
@@ -433,9 +433,9 @@ fn parse_eq_value<T: syn::parse::Parse>(input: ParseStream) -> Result<T, Error>
 /// strings (in order).
 fn extract_doc(attrs: &mut Vec<syn::Attribute>) -> Vec<String> {
     extract_attrs(attrs, |attr| {
-        match attr.parse_meta().ok()? {
+        match &attr.meta {
             syn::Meta::NameValue(syn::MetaNameValue {
-                lit: syn::Lit::Str(s),
+                value: syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Str(s), .. }),
                 path,
                 ..
             }) if path.is_ident("doc") => Some(s.value()),
@@ -447,7 +447,7 @@ fn extract_doc(attrs: &mut Vec<syn::Attribute>) -> Vec<String> {
 
 fn extract_config_attrs(attrs: &mut Vec<syn::Attribute>) -> Vec<syn::Attribute> {
     extract_attrs(attrs, |attr| {
-        if attr.path.is_ident("config") {
+        if attr.path().is_ident("config") {
             // TODO: clone not necessary once we use drain_filter
             Some(attr.clone())
         } else {