mirror of
https://github.com/pezkuwichain/pezkuwi-subxt.git
synced 2026-05-07 15:28:02 +00:00
Shawn Tabrizi
111 lines
3.3 KiB
Rust
111 lines
3.3 KiB
Rust
// Copyright 2019-2020 Parity Technologies (UK) Ltd.
|
|
// This file is part of Substrate.
|
|
|
|
// Substrate is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
|
|
// Substrate is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with Substrate. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
//! Derive macro implementation of `PassBy` with the associated type set to `Inner` and of the
|
|
//! helper trait `PassByInner`.
|
|
//!
|
|
//! It is required that the type is a newtype struct, otherwise an error is generated.
|
|
|
|
use crate::utils::{generate_crate_access, generate_runtime_interface_include};
|
|
|
|
use syn::{DeriveInput, Result, Generics, parse_quote, Type, Data, Error, Fields, Ident};
|
|
|
|
use quote::quote;
|
|
|
|
use proc_macro2::{TokenStream, Span};
|
|
|
|
/// The derive implementation for `PassBy` with `Inner` and `PassByInner`.
|
|
pub fn derive_impl(mut input: DeriveInput) -> Result<TokenStream> {
|
|
add_trait_bounds(&mut input.generics);
|
|
let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
|
|
let crate_include = generate_runtime_interface_include();
|
|
let crate_ = generate_crate_access();
|
|
let ident = input.ident;
|
|
let (inner_ty, inner_name) = extract_inner_ty_and_name(&input.data)?;
|
|
|
|
let access_inner = match inner_name {
|
|
Some(ref name) => quote!(self.#name),
|
|
None => quote!(self.0),
|
|
};
|
|
|
|
let from_inner = match inner_name {
|
|
Some(name) => quote!(Self { #name: inner }),
|
|
None => quote!(Self(inner)),
|
|
};
|
|
|
|
let res = quote! {
|
|
const _: () = {
|
|
#crate_include
|
|
|
|
impl #impl_generics #crate_::pass_by::PassBy for #ident #ty_generics #where_clause {
|
|
type PassBy = #crate_::pass_by::Inner<#ident, #inner_ty>;
|
|
}
|
|
|
|
impl #impl_generics #crate_::pass_by::PassByInner for #ident #ty_generics #where_clause {
|
|
type Inner = #inner_ty;
|
|
|
|
fn into_inner(self) -> Self::Inner {
|
|
#access_inner
|
|
}
|
|
|
|
fn inner(&self) -> &Self::Inner {
|
|
&#access_inner
|
|
}
|
|
|
|
fn from_inner(inner: Self::Inner) -> Self {
|
|
#from_inner
|
|
}
|
|
}
|
|
};
|
|
};
|
|
|
|
Ok(res)
|
|
}
|
|
|
|
/// Add the `RIType` trait bound to every type parameter.
|
|
fn add_trait_bounds(generics: &mut Generics) {
|
|
let crate_ = generate_crate_access();
|
|
|
|
generics.type_params_mut()
|
|
.for_each(|type_param| type_param.bounds.push(parse_quote!(#crate_::RIType)));
|
|
}
|
|
|
|
/// Extract the inner type and optional name from given input data.
|
|
///
|
|
/// It also checks that the input data is a newtype struct.
|
|
fn extract_inner_ty_and_name(data: &Data) -> Result<(Type, Option<Ident>)> {
|
|
if let Data::Struct(ref struct_data) = data {
|
|
match struct_data.fields {
|
|
Fields::Named(ref named) if named.named.len() == 1 => {
|
|
let field = &named.named[0];
|
|
return Ok((field.ty.clone(), field.ident.clone()))
|
|
},
|
|
Fields::Unnamed(ref unnamed) if unnamed.unnamed.len() == 1 => {
|
|
let field = &unnamed.unnamed[0];
|
|
return Ok((field.ty.clone(), field.ident.clone()))
|
|
}
|
|
_ => {},
|
|
}
|
|
}
|
|
|
|
Err(
|
|
Error::new(
|
|
Span::call_site(),
|
|
"Only newtype/one field structs are supported by `PassByInner`!",
|
|
)
|
|
)
|
|
}
|