1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49

use proc_macro::TokenStream;
use proc_macro2::{Ident, Span};
use quote::quote;
use syn::{parse_macro_input, Error};

// *Heavily* inspired by mlua's `lua_module` proc macro.
//
/// Marks the plugin entrypoint.
///
/// # Examples
///
/// ```ignore
/// use nvim_oxi as nvim;
///
/// #[nvim::module]
/// fn foo() -> nvim::Result<()> {
///     Ok(())
/// }
/// ```
#[proc_macro_attribute]
pub fn oxi_module(attr: TokenStream, item: TokenStream) -> TokenStream {
    let args = parse_macro_input!(attr as syn::AttributeArgs);

    if !args.is_empty() {
        return Error::new(Span::call_site(), "no attributes are supported")
            .to_compile_error()
            .into();
    }

    let item = parse_macro_input!(item as syn::ItemFn);

    let module_name = item.sig.ident.clone();

    let lua_module =
        Ident::new(&format!("luaopen_{module_name}"), Span::call_site());

    let module_body = quote! {
        #item

        #[no_mangle]
        unsafe extern "C" fn #lua_module(
            state: *mut ::nvim_oxi::lua::ffi::lua_State,
        ) -> ::std::ffi::c_int {
            ::nvim_oxi::entrypoint(state, #module_name)
        }
    };

    module_body.into()
}