|
| 1 | +use proc_macro::TokenStream; |
| 2 | +use proc_macro2::{Group, Span, TokenTree}; |
| 3 | +use quote::quote; |
| 4 | +use sha3::{Digest, Keccak256}; |
| 5 | +use std::collections::BTreeMap; |
| 6 | +use syn::{parse_macro_input, spanned::Spanned, DeriveInput}; |
| 7 | + |
| 8 | +fn parse_selector(signature_lit: syn::LitStr) -> u32 { |
| 9 | + let signature = signature_lit.value(); |
| 10 | + let digest = Keccak256::digest(signature.as_bytes()); |
| 11 | + let selector = u32::from_be_bytes([digest[0], digest[1], digest[2], digest[3]]); |
| 12 | + selector |
| 13 | +} |
| 14 | + |
| 15 | +fn parse_call_enum(input: DeriveInput) -> syn::Result<TokenStream> { |
| 16 | + let enum_ident = input.ident.clone(); |
| 17 | + let variants = if let syn::Data::Enum(syn::DataEnum { variants, .. }) = input.data { |
| 18 | + variants |
| 19 | + } else { |
| 20 | + return Err(syn::Error::new(input.ident.span(), "Structure not supported")); |
| 21 | + }; |
| 22 | + |
| 23 | + struct Call { |
| 24 | + variant: syn::Variant, |
| 25 | + } |
| 26 | + |
| 27 | + let mut selector_to_call = BTreeMap::new(); |
| 28 | + |
| 29 | + for v in variants { |
| 30 | + for a in &v.attrs { |
| 31 | + match a.parse_meta() { |
| 32 | + Ok(syn::Meta::NameValue(syn::MetaNameValue { |
| 33 | + path: syn::Path { segments, .. }, |
| 34 | + lit: syn::Lit::Str(signature_lit), |
| 35 | + .. |
| 36 | + })) if segments.first().filter(|path| path.ident == "selector").is_some() => { |
| 37 | + selector_to_call.insert(parse_selector(signature_lit), Call { variant: v.clone() }); |
| 38 | + for f in &v.fields { |
| 39 | + if f.ident.is_none() { |
| 40 | + return Err(syn::Error::new(f.span(), "Unnamed fields not supported")); |
| 41 | + } |
| 42 | + } |
| 43 | + } |
| 44 | + _ => return Err(syn::Error::new(a.span(), "Attribute not supported")), |
| 45 | + } |
| 46 | + } |
| 47 | + } |
| 48 | + |
| 49 | + let selectors: Vec<_> = selector_to_call.keys().collect(); |
| 50 | + let variants_ident: Vec<_> = selector_to_call |
| 51 | + .values() |
| 52 | + .map(|Call { variant, .. }| variant.ident.clone()) |
| 53 | + .collect(); |
| 54 | + let variants_args: Vec<Vec<_>> = selector_to_call |
| 55 | + .values() |
| 56 | + .map(|Call { variant, .. }| { |
| 57 | + variant |
| 58 | + .fields |
| 59 | + .iter() |
| 60 | + .map(|field| field.ident.clone().expect("Only named fields supported")) |
| 61 | + .collect() |
| 62 | + }) |
| 63 | + .collect(); |
| 64 | + |
| 65 | + Ok(quote! { |
| 66 | + impl #enum_ident { |
| 67 | + pub fn new(input: &[u8]) -> ::evm_utils::EvmResult<Self> { |
| 68 | + use ::evm_utils::RevertReason; |
| 69 | + |
| 70 | + let mut reader = ::evm_utils::Reader::new(input); |
| 71 | + let selector = reader.read_selector()?; |
| 72 | + match selector { |
| 73 | + #( |
| 74 | + #selectors => Ok(Self::#variants_ident { |
| 75 | + #( |
| 76 | + #variants_args: reader.read()? |
| 77 | + ),* |
| 78 | + }), |
| 79 | + )* |
| 80 | + _ => Err(RevertReason::UnknownSelector.into()) |
| 81 | + } |
| 82 | + } |
| 83 | + } |
| 84 | + } |
| 85 | + .into()) |
| 86 | +} |
| 87 | + |
| 88 | +#[proc_macro_derive(EvmCall, attributes(selector))] |
| 89 | +pub fn precompile_calls(input: TokenStream) -> TokenStream { |
| 90 | + let input = parse_macro_input!(input as DeriveInput); |
| 91 | + match parse_call_enum(input) { |
| 92 | + Ok(ts) => ts, |
| 93 | + Err(err) => err.to_compile_error().into(), |
| 94 | + } |
| 95 | +} |
| 96 | + |
| 97 | +fn parse_event_enum(input: DeriveInput) -> syn::Result<TokenStream> { |
| 98 | + let enum_ident = input.ident.clone(); |
| 99 | + let variants = if let syn::Data::Enum(syn::DataEnum { variants, .. }) = input.data { |
| 100 | + variants |
| 101 | + } else { |
| 102 | + return Err(syn::Error::new(input.ident.span(), "Structure not supported")); |
| 103 | + }; |
| 104 | + |
| 105 | + struct Event { |
| 106 | + variant: syn::Variant, |
| 107 | + topics: Vec<TokenTree>, |
| 108 | + // NOTE: we do not yet support tuple encoding |
| 109 | + data: Option<syn::Ident>, |
| 110 | + } |
| 111 | + |
| 112 | + let mut selector_to_event = BTreeMap::new(); |
| 113 | + |
| 114 | + for v in variants { |
| 115 | + for a in &v.attrs { |
| 116 | + match a.parse_meta() { |
| 117 | + Ok(syn::Meta::NameValue(syn::MetaNameValue { |
| 118 | + path: syn::Path { segments, .. }, |
| 119 | + lit: syn::Lit::Str(signature_lit), |
| 120 | + .. |
| 121 | + })) if segments.first().filter(|path| path.ident == "selector").is_some() => { |
| 122 | + let selector = Keccak256::digest(signature_lit.value().as_bytes()).to_vec(); |
| 123 | + selector_to_event.insert( |
| 124 | + selector.clone(), |
| 125 | + Event { |
| 126 | + variant: v.clone(), |
| 127 | + topics: vec![TokenTree::Group(Group::new( |
| 128 | + proc_macro2::Delimiter::Bracket, |
| 129 | + quote!(#(#selector),*), |
| 130 | + ))], |
| 131 | + data: None, |
| 132 | + }, |
| 133 | + ); |
| 134 | + if let syn::Fields::Named(syn::FieldsNamed { ref named, .. }) = v.fields { |
| 135 | + for n in named { |
| 136 | + let param = n |
| 137 | + .ident |
| 138 | + .clone() |
| 139 | + .ok_or(syn::Error::new(n.span(), "Unnamed fields not supported"))?; |
| 140 | + |
| 141 | + match n.attrs.first().map(|attr| attr.parse_meta()) { |
| 142 | + Some(Ok(syn::Meta::Path(syn::Path { segments, .. }))) |
| 143 | + if segments.first().filter(|path| path.ident == "indexed").is_some() => |
| 144 | + { |
| 145 | + if let Some(event) = selector_to_event.get_mut(&selector) { |
| 146 | + event.topics.push(TokenTree::Ident(param)) |
| 147 | + } |
| 148 | + } |
| 149 | + _ => { |
| 150 | + if let Some(event) = selector_to_event.get_mut(&selector) { |
| 151 | + if event.data.is_some() { |
| 152 | + return Err(syn::Error::new(n.span(), "Only one data field is allowed")); |
| 153 | + } else { |
| 154 | + event.data = Some(param) |
| 155 | + } |
| 156 | + } |
| 157 | + } |
| 158 | + } |
| 159 | + } |
| 160 | + } |
| 161 | + } |
| 162 | + _ => return Err(syn::Error::new(a.span(), "Attribute not supported")), |
| 163 | + } |
| 164 | + } |
| 165 | + } |
| 166 | + |
| 167 | + let variants_ident: Vec<_> = selector_to_event |
| 168 | + .values() |
| 169 | + .map(|Event { variant, .. }| variant.ident.clone()) |
| 170 | + .collect(); |
| 171 | + let variants_args: Vec<Vec<_>> = selector_to_event |
| 172 | + .values() |
| 173 | + .map(|Event { variant, .. }| { |
| 174 | + variant |
| 175 | + .fields |
| 176 | + .iter() |
| 177 | + .map(|arg| arg.ident.as_ref().expect("Named field")) |
| 178 | + .collect() |
| 179 | + }) |
| 180 | + .collect(); |
| 181 | + let topics: Vec<Vec<_>> = selector_to_event |
| 182 | + .values() |
| 183 | + .map(|Event { topics, .. }| topics.clone()) |
| 184 | + .collect(); |
| 185 | + let data: Vec<_> = selector_to_event |
| 186 | + .values() |
| 187 | + .map(|Event { data, .. }| { |
| 188 | + data.clone() |
| 189 | + .ok_or(syn::Error::new(Span::call_site(), "Requires data field")) |
| 190 | + }) |
| 191 | + .collect::<Result<_, _>>()?; |
| 192 | + |
| 193 | + Ok(quote! { |
| 194 | + impl #enum_ident { |
| 195 | + pub fn log(self, handle: &mut impl ::fp_evm::PrecompileHandle) -> ::evm_utils::EvmResult { |
| 196 | + let (topics, data): (Vec<::sp_core::H256>, _) = match self { |
| 197 | + #( |
| 198 | + Self::#variants_ident { #(#variants_args),* } => { |
| 199 | + (vec![#(#topics.into()),*], #data) |
| 200 | + }, |
| 201 | + )* |
| 202 | + }; |
| 203 | + |
| 204 | + let mut writer = ::evm_utils::Writer::new(); |
| 205 | + let data = writer.write(data).build(); |
| 206 | + |
| 207 | + handle.log( |
| 208 | + handle.context().address, |
| 209 | + topics, |
| 210 | + data, |
| 211 | + )?; |
| 212 | + Ok(()) |
| 213 | + } |
| 214 | + } |
| 215 | + } |
| 216 | + .into()) |
| 217 | +} |
| 218 | + |
| 219 | +#[proc_macro_derive(EvmEvent, attributes(selector, indexed, data))] |
| 220 | +pub fn precompile_events(input: TokenStream) -> TokenStream { |
| 221 | + let input = parse_macro_input!(input as DeriveInput); |
| 222 | + match parse_event_enum(input) { |
| 223 | + Ok(ts) => ts, |
| 224 | + Err(err) => err.to_compile_error().into(), |
| 225 | + } |
| 226 | +} |
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