ethers-rs/ethers-contract/ethers-contract-derive/src/calllike.rs

120 lines
4.0 KiB
Rust

//! Code used by both `call` and `error`
use crate::{abi_ty, utils};
use ethers_core::{
abi::Param,
macros::{ethers_contract_crate, ethers_core_crate},
};
use proc_macro2::{Ident, Span, TokenStream};
use quote::quote;
use syn::{DeriveInput, LitStr, Result};
/// All the attributes the `EthCall`/`EthError` macro supports
#[derive(Default)]
pub struct EthCalllikeAttributes {
pub name: Option<LitStr>,
pub abi: Option<LitStr>,
}
impl EthCalllikeAttributes {
pub fn name(&self, fallback: &Ident) -> String {
self.name.as_ref().map(|s| s.value()).unwrap_or_else(|| fallback.to_string())
}
pub fn abi(&self) -> Option<(String, Span)> {
self.abi.as_ref().map(|s| (s.value(), s.span()))
}
}
macro_rules! parse_calllike_attributes {
($input:ident, $attr_ident:literal) => {{
let mut result = EthCalllikeAttributes::default();
$crate::utils::parse_attributes!($input.attrs.iter(), $attr_ident, meta,
"name", result.name => {
meta.input.parse::<::syn::Token![=]>()?;
let litstr: ::syn::LitStr = meta.input.parse()?;
result.name = Some(litstr);
}
"abi", result.abi => {
meta.input.parse::<::syn::Token![=]>()?;
let litstr: ::syn::LitStr = meta.input.parse()?;
result.abi = Some(litstr);
}
);
result
}};
}
pub(crate) use parse_calllike_attributes;
/// Generates the decode implementation based on the type's runtime `AbiType` impl
pub fn derive_decode_impl_with_abi_type(
input: &DeriveInput,
trait_ident: Ident,
) -> Result<TokenStream> {
let datatypes_array = utils::abi_parameters_array(input, &trait_ident.to_string())?;
Ok(derive_decode_impl(datatypes_array, trait_ident))
}
/// Generates the decode implementation based on the params
pub fn derive_decode_impl_from_params(params: &[Param], trait_ident: Ident) -> TokenStream {
let datatypes = params.iter().map(|input| utils::param_type_quote(&input.kind));
let datatypes_array = quote! {[#( #datatypes ),*]};
derive_decode_impl(datatypes_array, trait_ident)
}
pub fn derive_decode_impl(datatypes_array: TokenStream, trait_ident: Ident) -> TokenStream {
let ethers_core = ethers_core_crate();
let ethers_contract = ethers_contract_crate();
let data_types_init = quote! {let data_types = #datatypes_array;};
quote! {
let bytes = bytes.as_ref();
if bytes.len() < 4 || bytes[..4] != <Self as #ethers_contract::#trait_ident>::selector() {
return Err(#ethers_contract::AbiError::WrongSelector);
}
#data_types_init
let data_tokens = #ethers_core::abi::decode(&data_types, &bytes[4..])?;
Ok(<Self as #ethers_core::abi::Tokenizable>::from_token(#ethers_core::abi::Token::Tuple(data_tokens))?)
}
}
/// Generates the Codec implementation
pub fn derive_codec_impls(
input: &DeriveInput,
decode_impl: TokenStream,
trait_ident: Ident,
) -> Result<TokenStream> {
// the ethers crates to use
let ethers_core = ethers_core_crate();
let ethers_contract = ethers_contract_crate();
let struct_name = &input.ident;
let codec_impl = quote! {
impl #ethers_core::abi::AbiDecode for #struct_name {
fn decode(bytes: impl AsRef<[u8]>) -> ::std::result::Result<Self, #ethers_core::abi::AbiError> {
#decode_impl
}
}
impl #ethers_core::abi::AbiEncode for #struct_name {
fn encode(self) -> ::std::vec::Vec<u8> {
let tokens = #ethers_core::abi::Tokenize::into_tokens(self);
let selector = <Self as #ethers_contract::#trait_ident>::selector();
let encoded = #ethers_core::abi::encode(&tokens);
selector
.iter()
.copied()
.chain(encoded.into_iter())
.collect()
}
}
};
let tokenize_impl = abi_ty::derive_tokenizeable_impl(input)?;
Ok(quote! {
#tokenize_impl
#codec_impl
})
}