upgrade to syn 2.x

Author: nikomatsakis

Cargo.lock

@@ -2,6 +2,8 @@
 name = "formality"
 version = "0.1.0"
 edition = "2021"
+license = "MIT OR APACHE-2"
+description = "Model of the Rust type system maintained by the Rust types team (in development)"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

Cargo.toml

@@ -2,6 +2,8 @@
 name = "formality-macros"
 version = "0.1.0"
 edition = "2021"
+license = "MIT OR APACHE-2"
+description = "Macros used by a-mir-formality and formality-core"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -11,8 +13,8 @@ proc-macro = true
 [dependencies]
 quote = "1.0.21"
 proc-macro2 = "1.0"
-syn = "1.0.102"
-synstructure = "0.12.6"
+syn = { version = "2.0", features = ["full"] }
+synstructure = "0.13.0"
 tracing = "0.1"
 convert_case = "0.6.0"
 

crates/formality-macros/Cargo.toml

@@ -91,5 +91,5 @@ fn downcast_to_variant(s: &synstructure::Structure, v: &VariantInfo) -> TokenStr
 }
 
 pub(crate) fn has_cast_attr(attrs: &[Attribute]) -> bool {
-    attrs.iter().any(|a| a.path.is_ident("cast"))
+    attrs.iter().any(|a| a.path().is_ident("cast"))
 }

crates/formality-macros/src/cast.rs

@@ -237,7 +237,7 @@ fn debug_variant_with_attr(
 }
 
 fn get_grammar_attr(attrs: &[Attribute]) -> Option<syn::Result<FormalitySpec>> {
-    let attr = attrs.iter().find(|a| a.path.is_ident("grammar"))?;
+    let attr = attrs.iter().find(|a| a.path().is_ident("grammar"))?;
     Some(attr.parse_args())
 }
 

crates/formality-macros/src/debug.rs

@@ -206,7 +206,7 @@ fn lookahead(for_field: &Ident, op: Option<&FormalitySpecOp>) -> syn::Result<Lit
 }
 
 fn get_grammar_attr(attrs: &[Attribute]) -> Option<syn::Result<FormalitySpec>> {
-    let attr = attrs.iter().find(|a| a.path.is_ident("grammar"))?;
+    let attr = attrs.iter().find(|a| a.path().is_ident("grammar"))?;
     Some(attr.parse_args())
 }
 

crates/formality-macros/src/parse.rs

@@ -40,7 +40,7 @@ fn remove_formality_attributes(input: &mut DeriveInput) {
         for variant in &mut v.variants {
             variant
                 .attrs
-                .retain(|attr| !attr.path.is_ident("grammar") && !attr.path.is_ident("cast"));
+                .retain(|attr| !attr.path().is_ident("grammar") && !attr.path().is_ident("cast"));
         }
     }
 }