openethereum/ipc/codegen/src/codegen.rs

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// Copyright 2015, 2016 Ethcore (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 aster;
use syntax::ast::{
MetaItem,
Item,
ImplItemKind,
ImplItem,
MethodSig,
Arg,
PatKind,
FunctionRetTy,
};
use syntax::ast;
use syntax::codemap::Span;
use syntax::ext::base::{Annotatable, ExtCtxt};
use syntax::ext::build::AstBuilder;
use syntax::ptr::P;
pub struct Error;
pub fn expand_ipc_implementation(
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cx: &mut ExtCtxt,
span: Span,
meta_item: &MetaItem,
annotatable: &Annotatable,
push: &mut FnMut(Annotatable)
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) {
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let item = match *annotatable {
Annotatable::Item(ref item) => item,
_ => {
cx.span_err(meta_item.span, "`#[derive(Ipc)]` may only be applied to struct implementations");
return;
}
};
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let builder = aster::AstBuilder::new().span(span);
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let impl_item = match implement_interface(cx, &builder, &item, push) {
Ok(item) => item,
Err(Error) => { return; }
};
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push(Annotatable::Item(impl_item))
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}
fn field_name(builder: &aster::AstBuilder, arg: &Arg) -> ast::Ident {
match arg.pat.node {
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PatKind::Ident(_, ref ident, _) => builder.id(ident.node),
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_ => { panic!("unexpected param in interface: {:?}", arg.pat.node) }
}
}
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fn push_invoke_signature_aster(
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builder: &aster::AstBuilder,
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implement: &ImplItem,
signature: &MethodSig,
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push: &mut FnMut(Annotatable),
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) -> Dispatch {
let inputs = &signature.decl.inputs;
let (input_type_name, input_arg_names) = if inputs.len() > 0 {
let first_field_name = field_name(builder, &inputs[0]).name.as_str();
if first_field_name == "self" && inputs.len() == 1 { (None, vec![]) }
else {
let skip = if first_field_name == "self" { 2 } else { 1 };
let name_str = format!("{}_input", implement.ident.name.as_str());
let mut arg_names = Vec::new();
let arg_name = format!("{}", field_name(builder, &inputs[skip-1]).name);
let mut tree = builder.item()
.attr().word("derive(Serialize, Deserialize)")
.attr().word("allow(non_camel_case_types)")
.struct_(name_str.as_str())
.field(arg_name.as_str()).ty().build(inputs[skip-1].ty.clone());
arg_names.push(arg_name);
for arg in inputs.iter().skip(skip) {
let arg_name = format!("{}", field_name(builder, &arg));
tree = tree.field(arg_name.as_str()).ty().build(arg.ty.clone());
arg_names.push(arg_name);
}
push(Annotatable::Item(tree.build()));
(Some(name_str.to_owned()), arg_names)
}
}
else {
(None, vec![])
};
let return_type_name = match signature.decl.output {
FunctionRetTy::Ty(ref ty) => {
let name_str = format!("{}_output", implement.ident.name.as_str());
let tree = builder.item()
.attr().word("derive(Serialize, Deserialize)")
.attr().word("allow(non_camel_case_types)")
.struct_(name_str.as_str())
.field(format!("payload")).ty().build(ty.clone());
push(Annotatable::Item(tree.build()));
Some(name_str.to_owned())
}
_ => None
};
Dispatch {
function_name: format!("{}", implement.ident.name.as_str()),
input_type_name: input_type_name,
input_arg_names: input_arg_names,
return_type_name: return_type_name,
}
}
struct Dispatch {
function_name: String,
input_type_name: Option<String>,
input_arg_names: Vec<String>,
return_type_name: Option<String>,
}
fn implement_dispatch_arm_invoke(
cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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dispatch: &Dispatch,
) -> P<ast::Expr>
{
let deserialize_expr = quote_expr!(cx, ::bincode::serde::deserialize_from(r, ::bincode::SizeLimit::Infinite).expect("ipc deserialization error, aborting"));
let input_type_id = builder.id(dispatch.input_type_name.clone().unwrap().as_str());
let function_name = builder.id(dispatch.function_name.as_str());
let output_type_id = builder.id(dispatch.return_type_name.clone().unwrap().as_str());
let input_args_exprs = dispatch.input_arg_names.iter().map(|ref arg_name| {
let arg_ident = builder.id(arg_name);
quote_expr!(cx, input. $arg_ident)
}).collect::<Vec<P<ast::Expr>>>();
// This is the expanded version of this:
//
// let invoke_serialize_stmt = quote_stmt!(cx, {
// ::bincode::serde::serialize(& $output_type_id { payload: self. $function_name ($hand_param_a, $hand_param_b) }, ::bincode::SizeLimit::Infinite).unwrap()
// });
//
// But the above does not allow comma-separated expressions for arbitrary number
// of parameters ...$hand_param_a, $hand_param_b, ... $hand_param_n
let invoke_serialize_stmt = {
let ext_cx = &*cx;
::quasi::parse_stmt_panic(&mut ::syntax::parse::new_parser_from_tts(
ext_cx.parse_sess(),
ext_cx.cfg(),
{
let _sp = ext_cx.call_site();
let mut tt = ::std::vec::Vec::new();
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Brace)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("bincode"), ::syntax::parse::token::ModName)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("serde"), ::syntax::parse::token::ModName)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("serialize"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::BinOp(::syntax::parse::token::And)));
tt.extend(::quasi::ToTokens::to_tokens(&output_type_id, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Brace)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("payload"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Colon));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("self"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Dot));
tt.extend(::quasi::ToTokens::to_tokens(&function_name, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Paren)));
for arg_expr in input_args_exprs {
tt.extend(::quasi::ToTokens::to_tokens(&arg_expr, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Comma));
}
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Brace)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Comma));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("bincode"), ::syntax::parse::token::ModName)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("SizeLimit"), ::syntax::parse::token::ModName)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::ModSep));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("Infinite"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Dot));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("unwrap"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Brace)));
tt
}))
};
quote_expr!(cx, {
let input: $input_type_id = $deserialize_expr;
$invoke_serialize_stmt
})
}
fn implement_dispatch_arm(cx: &ExtCtxt, builder: &aster::AstBuilder, index: u32, dispatch: &Dispatch)
-> ast::Arm
{
let index_ident = builder.id(format!("{}", index).as_str());
let invoke_expr = implement_dispatch_arm_invoke(cx, builder, dispatch);
quote_arm!(cx, $index_ident => { $invoke_expr } )
}
fn implement_interface(
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cx: &ExtCtxt,
builder: &aster::AstBuilder,
item: &Item,
push: &mut FnMut(Annotatable),
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) -> Result<P<ast::Item>, Error> {
let (generics, impl_items) = match item.node {
ast::ItemKind::Impl(_, _, ref generics, _, _, ref impl_items) => (generics, impl_items),
_ => {
cx.span_err(
item.span,
"`#[derive(Ipc)]` may only be applied to item implementations");
return Err(Error);
}
};
let impl_generics = builder.from_generics(generics.clone())
.add_ty_param_bound(
builder.path().global().ids(&["ethcore_ipc"]).build()
)
.build();
let ty = builder.ty().path()
.segment(item.ident).with_generics(impl_generics.clone()).build()
.build();
let where_clause = &impl_generics.where_clause;
let mut dispatch_table = Vec::new();
for impl_item in impl_items {
if let ImplItemKind::Method(ref signature, _) = impl_item.node {
dispatch_table.push(push_invoke_signature_aster(builder, &impl_item, signature, push));
}
}
let mut index = -1;
let dispatch_arms: Vec<_> = dispatch_table.iter()
.map(|dispatch| { index = index + 1; implement_dispatch_arm(cx, builder, index as u32, dispatch) }).collect();
Ok(quote_item!(cx,
impl $impl_generics ::ipc::IpcInterface<$ty> for $ty $where_clause {
fn dispatch<R>(&self, r: &mut R) -> Vec<u8>
where R: ::std::io::Read
{
let mut method_num = vec![0u8;2];
match r.read(&mut method_num) {
Ok(size) if size == 0 => { panic!("method id not supplied" ); }
Err(e) => { panic!("ipc read error: {:?}, aborting", e); }
_ => { }
}
match method_num[0] as u16 + (method_num[1] as u16)*256 {
$dispatch_arms
_ => vec![]
}
}
fn invoke<W>(&self, _method_num: u16, _payload: &Option<Vec<u8>>, _w: &mut W)
where W: ::std::io::Write
{
}
}
).unwrap())
}