Upgrade to syn 2.0 (#875)

* WIP updating to syn 2.0.0

* WIP darling compat

* Update darling and syn workspace deps

* NestedMeta::parse_meta_list

* Rename attribute keyword type property to path

* Fmt

* Update more type to path

* Unused darling

* Cargo.lock

* Add missing syn features

Author: ascjones

Cargo.lock

@@ -38,7 +38,7 @@ criterion = "0.4"
 codec = { package = "parity-scale-codec", version = "3.4.0", default-features = false }
 color-eyre = "0.6.1"
 console_error_panic_hook = "0.1.7"
-darling = "0.14.4"
+darling = "0.20.0"
 derivative = "2.2.0"
 either = "1.8.1"
 frame-metadata = { version = "15.1.0", features = ["v14", "v15-unstable", "std"] }
@@ -61,7 +61,7 @@ scale-decode = "0.5.0"
 scale-encode = "0.1.0"
 serde = { version = "1.0.159" }
 serde_json = { version = "1.0.96" }
-syn = "1.0.109"
+syn = { version = "2.0.15", features = ["full", "extra-traits"] }
 thiserror = "1.0.40"
 tokio = { version = "1.28", features = ["macros", "time", "rt-multi-thread"] }
 tracing = "0.1.34"

Cargo.toml

@@ -14,7 +14,6 @@ description = "Generate an API for interacting with a substrate node from FRAME
 
 [dependencies]
 codec = { package = "parity-scale-codec", workspace = true, features = ["derive"] }
-darling = { workspace = true }
 frame-metadata = { workspace = true }
 heck = { workspace = true }
 proc-macro2 = { workspace = true }

codegen/Cargo.toml

@@ -11,7 +11,6 @@ mod type_def;
 mod type_def_params;
 mod type_path;
 
-use darling::FromMeta;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::{quote, ToTokens};
 use scale_info::{form::PortableForm, PortableRegistry, Type, TypeDef};
@@ -353,7 +352,7 @@ impl ToTokens for CratePath {
 
 impl From<&str> for CratePath {
     fn from(crate_path: &str) -> Self {
-        Self(syn::Path::from_string(crate_path).unwrap_or_else(|err| {
+        Self(syn::parse_str(crate_path).unwrap_or_else(|err| {
             panic!("failed converting {crate_path:?} to `syn::Path`: {err:?}");
         }))
     }

codegen/src/types/mod.rs

@@ -17,8 +17,8 @@
     // mapping the type path to the derives which should be added for that type only.
     // Note that these derives will be in addition to those specified above in
     // `derive_for_all_types`
-    derive_for_type(type = "frame_support::PalletId", derive = "Eq, Ord, PartialOrd"),
-    derive_for_type(type = "sp_runtime::ModuleError", derive = "Eq, Hash"),
+    derive_for_type(path = "frame_support::PalletId", derive = "Eq, Ord, PartialOrd"),
+    derive_for_type(path = "sp_runtime::ModuleError", derive = "Eq, Hash"),
 )]
 pub mod polkadot {}
 

examples/examples/custom_type_derives.rs

@@ -31,7 +31,7 @@
 //! ```ignore
 //! #[subxt::subxt(
 //!     runtime_metadata_path = "polkadot_metadata.scale",
-//!     substitute_type(type = "sp_arithmetic::per_things::Perbill", with = "sp_runtime::Perbill")
+//!     substitute_type(path = "sp_arithmetic::per_things::Perbill", with = "sp_runtime::Perbill")
 //! )]
 //! pub mod polkadot {}
 //! ```
@@ -67,8 +67,8 @@
 //! #[subxt::subxt(
 //!     runtime_metadata_path = "polkadot_metadata.scale",
 //!     derive_for_all_types = "Eq, PartialEq",
-//!     derive_for_type(type = "frame_support::PalletId", derive = "Ord, PartialOrd"),
-//!     derive_for_type(type = "sp_runtime::ModuleError", derive = "Hash"),
+//!     derive_for_type(path = "frame_support::PalletId", derive = "Ord, PartialOrd"),
+//!     derive_for_type(path = "sp_runtime::ModuleError", derive = "Hash"),
 //! )]
 //! pub mod polkadot {}
 //! ```
@@ -113,7 +113,7 @@ extern crate proc_macro;
 
 use std::str::FromStr;
 
-use darling::FromMeta;
+use darling::{ast::NestedMeta, FromMeta};
 use proc_macro::TokenStream;
 use proc_macro_error::{abort_call_site, proc_macro_error};
 use subxt_codegen::{utils::Uri, CodegenError, DerivesRegistry, TypeSubstitutes};
@@ -158,29 +158,31 @@ struct RuntimeMetadataArgs {
 
 #[derive(Debug, FromMeta)]
 struct DeriveForType {
-    #[darling(rename = "type")]
-    ty: syn::TypePath,
+    path: syn::TypePath,
     derive: Punctuated<syn::Path, syn::Token![,]>,
 }
 
 #[derive(Debug, FromMeta)]
 struct AttributesForType {
-    #[darling(rename = "type")]
-    ty: syn::TypePath,
+    path: syn::TypePath,
     attributes: Punctuated<OuterAttribute, syn::Token![,]>,
 }
 
 #[derive(Debug, FromMeta)]
 struct SubstituteType {
-    #[darling(rename = "type")]
-    ty: syn::Path,
+    path: syn::Path,
     with: syn::Path,
 }
 
 #[proc_macro_attribute]
 #[proc_macro_error]
 pub fn subxt(args: TokenStream, input: TokenStream) -> TokenStream {
-    let attr_args = parse_macro_input!(args as syn::AttributeArgs);
+    let attr_args = match NestedMeta::parse_meta_list(args.into()) {
+        Ok(v) => v,
+        Err(e) => {
+            return TokenStream::from(darling::Error::from(e).write_errors());
+        }
+    };
     let item_mod = parse_macro_input!(input as syn::ItemMod);
     let args = match RuntimeMetadataArgs::from_list(&attr_args) {
         Ok(v) => v,
@@ -205,11 +207,15 @@ pub fn subxt(args: TokenStream, input: TokenStream) -> TokenStream {
     );
 
     for derives in &args.derive_for_type {
-        derives_registry.extend_for_type(derives.ty.clone(), derives.derive.iter().cloned(), vec![])
+        derives_registry.extend_for_type(
+            derives.path.clone(),
+            derives.derive.iter().cloned(),
+            vec![],
+        )
     }
     for attributes in &args.attributes_for_type {
         derives_registry.extend_for_type(
-            attributes.ty.clone(),
+            attributes.path.clone(),
             vec![],
             attributes.attributes.iter().map(|a| a.0.clone()),
         )
@@ -223,7 +229,7 @@ pub fn subxt(args: TokenStream, input: TokenStream) -> TokenStream {
     let substitute_args_res: Result<(), _> = args.substitute_type.into_iter().try_for_each(|sub| {
         sub.with
             .try_into()
-            .and_then(|with| type_substitutes.insert(sub.ty, with))
+            .and_then(|with| type_substitutes.insert(sub.path, with))
     });
 
     if let Err(err) = substitute_args_res {

macro/src/lib.rs

@@ -22,7 +22,7 @@ pub struct DoesntImplEncodeDecodeAsType(u16);
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Discarding both params:
         with = "crate::CustomAddress"
     )
@@ -32,7 +32,7 @@ pub mod node_runtime {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Discarding second param:
         with = "crate::Generic<A>"
     )
@@ -42,7 +42,7 @@ pub mod node_runtime2 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Discarding first param:
         with = "crate::Generic<B>"
     )
@@ -52,7 +52,7 @@ pub mod node_runtime3 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Swapping params:
         with = "crate::Second<B, A>"
     )
@@ -62,7 +62,7 @@ pub mod node_runtime4 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress",
+        path = "sp_runtime::multiaddress::MultiAddress",
         // Ignore input params and just use concrete types on output:
         with = "crate::Second<bool, ::std::vec::Vec<u8>>"
     )
@@ -72,7 +72,7 @@ pub mod node_runtime5 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // We can put a static type in, too:
         with = "crate::Second<B, u16>"
     )
@@ -82,7 +82,7 @@ pub mod node_runtime6 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Check that things can be wrapped in our Static type:
         with = "::subxt::utils::Static<crate::DoesntImplEncodeDecodeAsType>"
     )
@@ -92,7 +92,7 @@ pub mod node_runtime7 {}
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_runtime::multiaddress::MultiAddress<A, B>",
+        path = "sp_runtime::multiaddress::MultiAddress<A, B>",
         // Recursive type param substitution should work too (swapping out nested A and B):
         with = "::subxt::utils::Static<crate::Second<A, B>>"
     )

testing/ui-tests/src/correct/generic_params.rs

@@ -1,7 +1,7 @@
 #[subxt::subxt(
     runtime_metadata_path = "../../../../artifacts/polkadot_metadata.scale",
     substitute_type(
-        type = "sp_arithmetic::per_things::Perbill",
+        path = "sp_arithmetic::per_things::Perbill",
         with = "sp_runtime::Perbill"
     )
 )]