C++: --enable-cxx-namespaces can fail to generate type aliases

[sanxiyn]

Input C/C++ Header

namespace ns {
enum class AB { A, B };
}
using AB = ns::AB;
static const AB kA = AB::A;

Bindgen Invocation

$ bindgen input.h --enable-cxx-namespaces -- -x c++

Actual Results

/* automatically generated by rust-bindgen */

#[allow(non_snake_case, non_camel_case_types, non_upper_case_globals)]
pub mod root {
    #[allow(unused_imports)]
    use self::super::root;
    pub mod ns {
        #[allow(unused_imports)]
        use self::super::super::root;
        pub const AB_A: root::ns::AB = 0;
        pub const AB_B: root::ns::AB = 1;
        pub type AB = i32;
    }
    extern "C" {
        #[link_name = "\u{1}kA"]
        pub static kA: root::AB;
    }
}

Expected Results

The output does not compile. It seems to me something like pub use root::ns::AB as AB; is missing.

[sanxiyn]

Investigation

There is no problem if --enable-cxx-namespaces is not used.

There is no problem if using ABC = ns::AB; is used instead.

[sanxiyn]

Looking at codegen for TypeKind::Alias in src/codegen/mod.rs, it seems to me code to handle #946 should compare canonical path, not canonical name, but I am not familiar enough with bindgen codebase to be sure.

[emilio]

Yes, that sounds right, nice catch!

Wanna submit a patch? :)

[sanxiyn]

Wow, thanks for a super fast reply!

Given my analysis is correct, I should be able to come up with a patch. Please wait a minute. :)