From c290293cf291951825b10830df4bce3bc03aabef Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Wed, 16 Oct 2019 10:33:16 +1100 Subject: Derive `Rustc{En,De}codable` for `TokenStream`. `TokenStream` used to be a complex type, but it is now just a newtype around a `Lrc>`. Currently it uses custom encoding that discards the `IsJoint` and custom decoding that adds `NonJoint` back in for every token tree. This requires building intermediate `Vec`s. This commit makes `TokenStream` derive `Rustc{En,De}codable`. This simplifies the code, and avoids the creation of the intermediate vectors, saving up to 3% on various benchmarks. It also changes the AST JSON output in one test. --- src/libsyntax/tokenstream.rs | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) (limited to 'src/libsyntax') diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs index ac155556cda..0559f224f1f 100644 --- a/src/libsyntax/tokenstream.rs +++ b/src/libsyntax/tokenstream.rs @@ -19,7 +19,6 @@ use syntax_pos::{BytePos, Span, DUMMY_SP}; #[cfg(target_arch = "x86_64")] use rustc_data_structures::static_assert_size; use rustc_data_structures::sync::Lrc; -use rustc_serialize::{Decoder, Decodable, Encoder, Encodable}; use smallvec::{SmallVec, smallvec}; use std::{iter, mem}; @@ -136,7 +135,7 @@ impl TokenTree { /// The goal is for procedural macros to work with `TokenStream`s and `TokenTree`s /// instead of a representation of the abstract syntax tree. /// Today's `TokenTree`s can still contain AST via `token::Interpolated` for back-compat. -#[derive(Clone, Debug, Default)] +#[derive(Clone, Debug, Default, RustcEncodable, RustcDecodable)] pub struct TokenStream(pub Lrc>); pub type TreeAndJoint = (TokenTree, IsJoint); @@ -145,7 +144,7 @@ pub type TreeAndJoint = (TokenTree, IsJoint); #[cfg(target_arch = "x86_64")] static_assert_size!(TokenStream, 8); -#[derive(Clone, Copy, Debug, PartialEq)] +#[derive(Clone, Copy, Debug, PartialEq, RustcEncodable, RustcDecodable)] pub enum IsJoint { Joint, NonJoint @@ -460,18 +459,6 @@ impl Cursor { } } -impl Encodable for TokenStream { - fn encode(&self, encoder: &mut E) -> Result<(), E::Error> { - self.trees().collect::>().encode(encoder) - } -} - -impl Decodable for TokenStream { - fn decode(decoder: &mut D) -> Result { - Vec::::decode(decoder).map(|vec| vec.into_iter().collect()) - } -} - #[derive(Debug, Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)] pub struct DelimSpan { pub open: Span, -- cgit 1.4.1-3-g733a5