napi_derive_backend/codegen/
const.rs

1use proc_macro2::{Ident, Literal, TokenStream};
2use quote::ToTokens;
3
4use crate::{codegen::js_mod_to_token_stream, BindgenResult, NapiConst, TryToTokens};
5
6impl TryToTokens for NapiConst {
7  fn try_to_tokens(&self, tokens: &mut TokenStream) -> BindgenResult<()> {
8    let register = self.gen_module_register();
9    (quote! {
10      #register
11    })
12    .to_tokens(tokens);
13
14    Ok(())
15  }
16}
17
18impl NapiConst {
19  fn gen_module_register(&self) -> TokenStream {
20    let name_ident = &self.name;
21    let js_name_lit = Literal::string(&format!("{}\0", self.name));
22    let register_name = &self.register_name;
23    let type_name = &self.type_name;
24    let cb_name = Ident::new(
25      &format!("__register__const__{}_callback__", register_name),
26      self.name.span(),
27    );
28    let js_mod_ident = js_mod_to_token_stream(self.js_mod.as_ref());
29
30    quote! {
31      #[allow(non_snake_case)]
32      #[allow(clippy::all)]
33      unsafe fn #cb_name(env: napi::sys::napi_env) -> napi::Result<napi::sys::napi_value> {
34        <#type_name as napi::bindgen_prelude::ToNapiValue>::to_napi_value(env, #name_ident)
35      }
36      #[allow(non_snake_case)]
37      #[allow(clippy::all)]
38      #[cfg(all(not(test), not(target_family = "wasm")))]
39      #[napi::bindgen_prelude::ctor]
40      fn #register_name() {
41        napi::bindgen_prelude::register_module_export(#js_mod_ident, #js_name_lit, #cb_name);
42      }
43
44      #[allow(non_snake_case)]
45      #[allow(clippy::all)]
46      #[cfg(all(not(test), target_family = "wasm"))]
47      #[no_mangle]
48      unsafe extern "C" fn #register_name() {
49        napi::bindgen_prelude::register_module_export(#js_mod_ident, #js_name_lit, #cb_name);
50      }
51    }
52  }
53}