libipld_cbor_derive/
lib.rs

1use proc_macro2::{Span, TokenStream};
2use proc_macro_crate::{crate_name, FoundCrate};
3use quote::quote;
4use synstructure::{decl_derive, Structure};
5
6decl_derive!([DagCbor, attributes(ipld)] => dag_cbor_derive);
7
8mod ast;
9mod attr;
10mod gen;
11mod parse;
12
13fn dag_cbor_derive(s: Structure) -> TokenStream {
14    let libipld = match use_crate("libipld") {
15        Ok(ident) => ident,
16        Err(error) => return error,
17    };
18    let ast = parse::parse(&s);
19    let encode = gen::gen_encode(&ast, &libipld);
20    let decode = gen::gen_decode(&ast, &libipld);
21    quote! {
22        #encode
23        #decode
24    }
25}
26
27/// Get the name of a crate based on its original name.
28///
29/// This works even if the crate was renamed in the `Cargo.toml` file. If the crate is not a
30/// dependency, it will lead to a compile-time error.
31fn use_crate(name: &str) -> Result<syn::Ident, TokenStream> {
32    match crate_name(name) {
33        Ok(FoundCrate::Name(n)) => Ok(syn::Ident::new(&n, Span::call_site())),
34        Ok(FoundCrate::Itself) => Ok(syn::Ident::new("crate", Span::call_site())),
35        Err(err) => Err(syn::Error::new(Span::call_site(), err).to_compile_error()),
36    }
37}
38
39#[cfg(test)]
40mod tests {
41    #[test]
42    fn test() {
43        let t = trybuild::TestCases::new();
44        t.pass("examples/basic.rs");
45        t.pass("examples/name_attr.rs");
46        t.pass("examples/repr_attr.rs");
47    }
48}
libipld_cbor_derive/lib.rs

libipld_cbor_derive/
lib.rs
