// SPDX-License-Identifier: GPL-2.0
use crate::helpers::function_name;
use proc_macro::TokenStream;
/// Please see [`crate::export`] for documentation.
pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream {
let Some(name) = function_name(ts.clone()) else {
return "::core::compile_error!(\"The #[export] attribute must be used on a function.\");"
.parse::<TokenStream>()
.unwrap();
};
// This verifies that the function has the same signature as the declaration generated by
// bindgen. It makes use of the fact that all branches of an if/else must have the same type.
let signature_check = quote!(
const _: () = {
if true {
::kernel::bindings::#name
} else {
#name
};
};
);
let no_mangle = quote!(#[no_mangle]);
TokenStream::from_iter([signature_check, no_mangle, ts])
}