Parse unsafe in attributes

[Coekjan]

See https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#unsafe-attributes

Now attributes can contain unsafe, but cbindgen gives the following error:

ParseSyntaxError { crate_name: "...", src_path: "...", error: Error("expected identifier, found keyword `unsafe`") }

I think this issue could be urgent (should be done before edition 2024), because programmers, like me, may write:

#[unsafe(export_name = "xxx")]
pub fn f() {

}

Current rust stable (1.82.x) introduces this syntax and recommends us to add unsafe, while the old form (without unsafe) is still acceptable. But the old form will be a hard error in edition 2024.

---

This issue seems actually from upstream: dtolnay/syn#1710

[Coekjan]

Because dtolnay/syn#1710 is done, all we need is to wait for the next release of syn.

[qryxip]

Not yet completed, I think. The current cbindgen itself does not know unsafe attributes.

cbindgen/src/bindgen/utilities.rs

Lines 196 to 198 in 3ed9434

	fn is_no_mangle(&self) -> bool {
	self.has_attr_word("no_mangle")
	}

They are now parsed indeed, but just skipped.

[Coekjan]

Not yet completed, I think. The current cbindgen itself does not know unsafe attributes.

cbindgen/src/bindgen/utilities.rs

Lines 196 to 198 in 3ed9434

	fn is_no_mangle(&self) -> bool {
	self.has_attr_word("no_mangle")
	}

They are now parsed indeed, but just skipped.

Yes, you are right. cbindgen should visit the inner of the unsafe attributes.

[emilio]

Fixed by #1020, thanks @Coekjan!

[Coekjan]

Fixed by #1020, thanks @Coekjan!

@emilio Could you please make a new release? My project needs this feature (to parse unsafe attributes).