Use error reporting provided by Meta

Author: dtolnay

gen/build/Cargo.toml

@@ -25,7 +25,7 @@ once_cell = "1.9"
 proc-macro2 = { version = "1.0.39", default-features = false, features = ["span-locations"] }
 quote = { version = "1.0", default-features = false }
 scratch = "1.0"
-syn = { version = "2.0.0", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
+syn = { version = "2.0.1", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
 
 [dev-dependencies]
 cxx = { version = "1.0", path = "../.." }

gen/cmd/Cargo.toml

@@ -25,7 +25,7 @@ clap = { version = "4", default-features = false, features = ["error-context", "
 codespan-reporting = "0.11"
 proc-macro2 = { version = "1.0.39", default-features = false, features = ["span-locations"] }
 quote = { version = "1.0", default-features = false }
-syn = { version = "2.0.0", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
+syn = { version = "2.0.1", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]

gen/lib/Cargo.toml

@@ -15,7 +15,7 @@ rust-version = "1.60"
 codespan-reporting = "0.11"
 proc-macro2 = { version = "1.0.39", default-features = false, features = ["span-locations"] }
 quote = { version = "1.0", default-features = false }
-syn = { version = "2.0.0", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
+syn = { version = "2.0.1", default-features = false, features = ["parsing", "printing", "clone-impls", "full"] }
 
 [lib]
 doc-scrape-examples = false

macro/Cargo.toml

@@ -23,7 +23,7 @@ experimental-enum-variants-from-header = ["clang-ast", "flate2", "memmap", "serd
 [dependencies]
 proc-macro2 = "1.0.39"
 quote = "1.0.4"
-syn = { version = "2.0.0", features = ["full"] }
+syn = { version = "2.0.1", features = ["full"] }
 
 # optional dependencies:
 clang-ast = { version = "0.1", optional = true }

syntax/attrs.rs

@@ -146,7 +146,7 @@ pub fn parse(cx: &mut Errors, attrs: Vec<Attribute>, mut parser: Parser) -> Othe
         } else if attr_path.is_ident("variants_from_header")
             && cfg!(feature = "experimental-enum-variants-from-header")
         {
-            if let Err(err) = require_empty_attribute(&attr.meta) {
+            if let Err(err) = attr.meta.require_path_only() {
                 cx.push(err);
             }
             if let Some(variants_from_header) = &mut parser.variants_from_header {
@@ -310,12 +310,3 @@ impl ToTokens for OtherAttrs {
         }
     }
 }
-
-fn require_empty_attribute(meta: &Meta) -> Result<()> {
-    let error_span = match meta {
-        Meta::Path(_) => return Ok(()),
-        Meta::List(meta) => meta.delimiter.span().open(),
-        Meta::NameValue(meta) => meta.eq_token.span,
-    };
-    Err(Error::new(error_span, "unexpected token in cxx attribute"))
-}

third-party/BUCK

@@ -15,4 +15,4 @@ once_cell = "1.9"
 proc-macro2 = { version = "1.0.39", features = ["span-locations"] }
 quote = "1.0.4"
 scratch = "1"
-syn = { version = "2.0.0", features = ["full"] }
+syn = { version = "2.0.1", features = ["full"] }