Update syn to 2.0

.github/workflows/rust.yml

@@ -57,7 +57,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: "1.66"
+          toolchain: "1.68"
         id: rust-toolchain
       - uses: actions/cache@v3
         with:

Cargo.toml

@@ -37,5 +37,5 @@ uuid08 = { package = "uuid", version = "0.8", optional = true }
 [dev-dependencies]
 paste = "1.0"
 pretty_assertions = "1.0"
-serde = { version = "1.0", features = ["derive"] }
+serde = { version = "1.0.158", features = ["derive"] }
 trybuild = "=1.0.79"

derive/Cargo.toml

@@ -17,6 +17,6 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-serde_derive_internals = "0.26"
-syn = "1.0"
-syn-path = "1.0"
+serde_derive_internals = "0.27"
+syn = "2.0"
+syn-path = "2.0"

derive/src/attrs.rs

@@ -1,12 +1,16 @@
 use crate::util::ExpectLit;
-use syn::{punctuated::Punctuated, spanned::Spanned as _, Attribute, LitStr, Meta, Token};
+use proc_macro2::TokenStream;
+use syn::{
+	parse::{Parse, ParseStream},
+	punctuated::Punctuated,
+	spanned::Spanned as _,
+	Attribute, LitStr, Meta, Token
+};
 
 pub(super) fn parse_doc_attr(input: &Attribute) -> syn::Result<Option<LitStr>> {
-	input.parse_meta().and_then(|meta| {
-		Ok(match meta {
-			Meta::NameValue(kv) => Some(kv.lit.expect_str()?),
-			_ => None
-		})
+	Ok(match &input.meta {
+		Meta::NameValue(kv) => Some(kv.value.clone().expect_str()?),
+		_ => None
 	})
 }
 
@@ -36,25 +40,33 @@ pub(super) struct ContainerAttributes {
 	pub(super) deny_unknown_fields: bool
 }
 
+struct ParseHelper(Punctuated<Meta, Token![,]>);
+
+impl Parse for ParseHelper {
+	fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
+		Ok(Self(Punctuated::parse_terminated(input)?))
+	}
+}
+
 impl ContainerAttributes {
-	pub(super) fn parse_from(&mut self, input: &Attribute, error_on_unknown: bool) -> syn::Result<()> {
-		let tokens: Punctuated<Meta, Token![,]> = input.parse_args_with(Punctuated::parse_terminated)?;
+	pub(super) fn parse_from(&mut self, tokens: TokenStream, error_on_unknown: bool) -> syn::Result<()> {
+		let tokens = syn::parse2::<ParseHelper>(tokens)?.0;
 		for token in tokens {
 			match token {
 				Meta::NameValue(kv) if kv.path.is_ident("rename") => {
-					self.rename = Some(kv.lit.expect_str()?);
+					self.rename = Some(kv.value.expect_str()?);
 				},
 
 				Meta::NameValue(kv) if kv.path.is_ident("rename_all") => {
-					self.rename_all = Some(kv.lit.expect_str()?);
+					self.rename_all = Some(kv.value.expect_str()?);
 				},
 
 				Meta::NameValue(kv) if kv.path.is_ident("tag") => {
-					self.tag = Some(kv.lit.expect_str()?);
+					self.tag = Some(kv.value.expect_str()?);
 				},
 
 				Meta::NameValue(kv) if kv.path.is_ident("content") => {
-					self.content = Some(kv.lit.expect_str()?);
+					self.content = Some(kv.value.expect_str()?);
 				},
 
 				Meta::Path(path) if path.is_ident("untagged") => {
@@ -87,12 +99,12 @@ pub(super) struct FieldAttributes {
 }
 
 impl FieldAttributes {
-	pub(super) fn parse_from(&mut self, input: &Attribute, error_on_unknown: bool) -> syn::Result<()> {
-		let tokens: Punctuated<Meta, Token![,]> = input.parse_args_with(Punctuated::parse_terminated)?;
+	pub(super) fn parse_from(&mut self, tokens: TokenStream, error_on_unknown: bool) -> syn::Result<()> {
+		let tokens = syn::parse2::<ParseHelper>(tokens)?.0;
 		for token in tokens {
 			match token {
 				Meta::NameValue(kv) if kv.path.is_ident("rename") => {
-					self.rename = Some(kv.lit.expect_str()?);
+					self.rename = Some(kv.value.expect_str()?);
 				},
 
 				Meta::Path(path) if path.is_ident("default") => {

derive/src/lib.rs

@@ -8,7 +8,7 @@
 use proc_macro::TokenStream;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
-use syn::{parse_macro_input, Data, DeriveInput, TraitBound, TraitBoundModifier, TypeParamBound};
+use syn::{parse_macro_input, Data, DeriveInput, Meta, TraitBound, TraitBoundModifier, TypeParamBound};
 use syn_path::path;
 
 mod attrs;
@@ -28,25 +28,34 @@ pub fn derive_openapi_type(input: TokenStream) -> TokenStream {
 	expand_openapi_type(input).unwrap_or_else(|err| err.to_compile_error()).into()
 }
 
+fn filter_parse_attrs(
+	attrs: &mut ContainerAttributes,
+	input: &DeriveInput,
+	filter: &str,
+	error_on_unknown: bool
+) -> syn::Result<()> {
+	for attr in &input.attrs {
+		match &attr.meta {
+			Meta::List(meta) if meta.path.is_ident(filter) => {
+				attrs.parse_from(meta.tokens.clone(), error_on_unknown)?;
+			},
+			_ => {}
+		}
+	}
+	Ok(())
+}
+
 fn expand_openapi_type(mut input: DeriveInput) -> syn::Result<TokenStream2> {
 	let ident = &input.ident;
 
 	// parse #[serde] and #[openapi] attributes
 	let mut attrs = ContainerAttributes::default();
-	for attr in &input.attrs {
-		if attr.path.is_ident("serde") {
-			attrs.parse_from(attr, false)?;
-		}
-	}
-	for attr in &input.attrs {
-		if attr.path.is_ident("openapi") {
-			attrs.parse_from(attr, true)?;
-		}
-	}
+	filter_parse_attrs(&mut attrs, &input, "serde", false)?;
+	filter_parse_attrs(&mut attrs, &input, "openapi", true)?;
 
 	// parse #[doc] attributes
 	for attr in &input.attrs {
-		if attr.path.is_ident("doc") {
+		if attr.path().is_ident("doc") {
 			if let Some(lit) = parse_doc_attr(attr)? {
 				attrs.doc.push(lit.value());
 			}

derive/src/parser.rs

@@ -5,8 +5,8 @@ use crate::{
 use proc_macro2::{Ident, Span};
 use serde_derive_internals::attr::RenameRule;
 use syn::{
-	punctuated::Punctuated, spanned::Spanned as _, AngleBracketedGenericArguments, DataEnum, DataStruct, DataUnion, Fields,
-	FieldsNamed, GenericArgument, LitStr, PathArguments, Type, TypePath
+	punctuated::Punctuated, spanned::Spanned as _, AngleBracketedGenericArguments, DataEnum, DataStruct, DataUnion, Field,
+	Fields, FieldsNamed, GenericArgument, LitStr, Meta, PathArguments, Type, TypePath
 };
 use syn_path::path;
 
@@ -43,21 +43,25 @@ pub(super) enum ParseDataType {
 	Unit
 }
 
+fn filter_parse_attrs(attrs: &mut FieldAttributes, input: &Field, filter: &str, error_on_unknown: bool) -> syn::Result<()> {
+	for attr in &input.attrs {
+		match &attr.meta {
+			Meta::List(meta) if meta.path.is_ident(filter) => {
+				attrs.parse_from(meta.tokens.clone(), error_on_unknown)?;
+			},
+			_ => {}
+		}
+	}
+	Ok(())
+}
+
 fn parse_named_fields(named_fields: &FieldsNamed, rename_all: Option<&LitStr>) -> syn::Result<Vec<ParseDataField>> {
 	let mut fields: Vec<ParseDataField> = Vec::new();
 	for f in &named_fields.named {
 		// parse #[serde] and #[openapi] attributes
 		let mut attrs = FieldAttributes::default();
-		for attr in &f.attrs {
-			if attr.path.is_ident("serde") {
-				attrs.parse_from(attr, false)?;
-			}
-		}
-		for attr in &f.attrs {
-			if attr.path.is_ident("openapi") {
-				attrs.parse_from(attr, true)?;
-			}
-		}
+		filter_parse_attrs(&mut attrs, f, "serde", false)?;
+		filter_parse_attrs(&mut attrs, f, "openapi", true)?;
 
 		// skip this field if desired
 		if attrs.skip_serializing && attrs.skip_deserializing {
@@ -67,7 +71,7 @@ fn parse_named_fields(named_fields: &FieldsNamed, rename_all: Option<&LitStr>) -
 		// parse #[doc] attributes
 		let mut doc = Vec::new();
 		for attr in &f.attrs {
-			if attr.path.is_ident("doc") {
+			if attr.path().is_ident("doc") {
 				if let Some(lit) = parse_doc_attr(attr)? {
 					doc.push(lit.value());
 				}
@@ -339,7 +343,7 @@ pub(super) fn parse_enum(ident: &Ident, inum: &DataEnum, attrs: &ContainerAttrib
 		},
 		// no variants
 		(None, None) => Err(syn::Error::new(
-			inum.brace_token.span,
+			inum.brace_token.span.span(),
 			"#[derive(OpenapiType)] does not support enums with no variants"
 		))
 	}

derive/src/util.rs

@@ -1,5 +1,5 @@
 use proc_macro2::{Ident, Span};
-use syn::{Lit, LitStr};
+use syn::{spanned::Spanned as _, Expr, Lit, LitStr};
 
 /// Convert [Ident], [String] and [&str] into a [LitStr].
 pub(super) trait ToLitStr {
@@ -37,3 +37,12 @@ impl ExpectLit for Lit {
 		}
 	}
 }
+
+impl ExpectLit for Expr {
+	fn expect_str(self) -> syn::Result<LitStr> {
+		match self {
+			Expr::Lit(lit) => lit.lit.expect_str(),
+			_ => Err(syn::Error::new(self.span(), "Expected string literal"))
+		}
+	}
+}

tests/fail/not_openapitype_generics.stderr

@@ -15,11 +15,9 @@ error[E0599]: the function or associated item `schema` exists for struct `Foo<Ba
    |
    = note: trait bound `Bar: OpenapiType` was not satisfied
    = note: the following trait bounds were not satisfied:
-           `Bar: OpenapiType`
-           which is required by `Foo<Bar>: OpenapiType`
            `Foo<Bar>: OpenapiType`
            which is required by `&Foo<Bar>: OpenapiType`
-note: the following trait must be implemented
+note: the trait `OpenapiType` must be implemented
   --> src/lib.rs
    |
    | pub trait OpenapiType {