openethereum/util/rlp_derive/src/en.rs
Niklas Adolfsson 98b7c07171 Update license header and scripts (#8666)
* Update `add_license` script

* run script

* add `remove duplicate lines script` and run it

* Revert changes `English spaces`

* strip whitespaces

* Revert `GPL` in files with `apache/mit license`

* don't append `gpl license` in files with other lic

* Don't append `gpl header` in files with other lic.

* re-ran script

* include c and cpp files too

* remove duplicate header

* rebase nit
2018-06-04 10:19:50 +02:00

123 lines
3.7 KiB
Rust

// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity 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.
// Parity 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 Parity. If not, see <http://www.gnu.org/licenses/>.
use {syn, quote};
pub fn impl_encodable(ast: &syn::DeriveInput) -> quote::Tokens {
let body = match ast.data {
syn::Data::Struct(ref s) => s,
_ => panic!("#[derive(RlpEncodable)] is only defined for structs."),
};
let stmts: Vec<_> = body.fields.iter().enumerate().map(encodable_field_map).collect();
let name = &ast.ident;
let stmts_len = stmts.len();
let stmts_len = quote! { #stmts_len };
let dummy_const: syn::Ident = format!("_IMPL_RLP_ENCODABLE_FOR_{}", name).into();
let impl_block = quote! {
impl rlp::Encodable for #name {
fn rlp_append(&self, stream: &mut rlp::RlpStream) {
stream.begin_list(#stmts_len);
#(#stmts)*
}
}
};
quote! {
#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
const #dummy_const: () = {
extern crate rlp;
#impl_block
};
}
}
pub fn impl_encodable_wrapper(ast: &syn::DeriveInput) -> quote::Tokens {
let body = match ast.data {
syn::Data::Struct(ref s) => s,
_ => panic!("#[derive(RlpEncodableWrapper)] is only defined for structs."),
};
let stmt = {
let fields: Vec<_> = body.fields.iter().collect();
if fields.len() == 1 {
let field = fields.first().expect("fields.len() == 1; qed");
encodable_field(0, field)
} else {
panic!("#[derive(RlpEncodableWrapper)] is only defined for structs with one field.")
}
};
let name = &ast.ident;
let dummy_const: syn::Ident = format!("_IMPL_RLP_ENCODABLE_FOR_{}", name).into();
let impl_block = quote! {
impl rlp::Encodable for #name {
fn rlp_append(&self, stream: &mut rlp::RlpStream) {
#stmt
}
}
};
quote! {
#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
const #dummy_const: () = {
extern crate rlp;
#impl_block
};
}
}
fn encodable_field_map(tuple: (usize, &syn::Field)) -> quote::Tokens {
encodable_field(tuple.0, tuple.1)
}
fn encodable_field(index: usize, field: &syn::Field) -> quote::Tokens {
let ident = match field.ident {
Some(ref ident) => quote! { #ident },
None => {
let index: syn::Index = index.into();
quote! { #index }
}
};
let id = quote! { self.#ident };
match field.ty {
syn::Type::Path(ref path) => {
let top_segment = path.path.segments.first().expect("there must be at least 1 segment");
let ident = &top_segment.value().ident;
if &ident.to_string() == "Vec" {
let inner_ident = match top_segment.value().arguments {
syn::PathArguments::AngleBracketed(ref angle) => {
let ty = angle.args.first().expect("Vec has only one angle bracketed type; qed");
match **ty.value() {
syn::GenericArgument::Type(syn::Type::Path(ref path)) => &path.path.segments.first().expect("there must be at least 1 segment").value().ident,
_ => panic!("rlp_derive not supported"),
}
},
_ => unreachable!("Vec has only one angle bracketed type; qed"),
};
quote! { stream.append_list::<#inner_ident, _>(&#id); }
} else {
quote! { stream.append(&#id); }
}
},
_ => panic!("rlp_derive not supported"),
}
}