From d05e4d2c9bc096932dae8502a72fe831b9872ae3 Mon Sep 17 00:00:00 2001 From: Alan Egerton Date: Sun, 28 Nov 2021 18:41:04 +0000 Subject: [PATCH] Avoid uneccessary clone of Annotatable --- compiler/rustc_builtin_macros/src/cfg_eval.rs | 52 +++++++++++-------- 1 file changed, 30 insertions(+), 22 deletions(-) diff --git a/compiler/rustc_builtin_macros/src/cfg_eval.rs b/compiler/rustc_builtin_macros/src/cfg_eval.rs index 307730f7f5f14..8cc761dfd513a 100644 --- a/compiler/rustc_builtin_macros/src/cfg_eval.rs +++ b/compiler/rustc_builtin_macros/src/cfg_eval.rs @@ -11,7 +11,7 @@ use rustc_expand::base::{Annotatable, ExtCtxt}; use rustc_expand::config::StripUnconfigured; use rustc_expand::configure; use rustc_feature::Features; -use rustc_parse::parser::ForceCollect; +use rustc_parse::parser::{ForceCollect, Parser}; use rustc_session::utils::FlattenNonterminals; use rustc_session::Session; use rustc_span::symbol::sym; @@ -138,8 +138,34 @@ impl CfgEval<'_, '_> { // the location of `#[cfg]` and `#[cfg_attr]` in the token stream. The tokenization // process is lossless, so this process is invisible to proc-macros. - // FIXME - get rid of this clone - let nt = annotatable.clone().into_nonterminal(); + let parse_annotatable_with: fn(&mut Parser<'_>) -> _ = match annotatable { + Annotatable::Item(_) => { + |parser| Annotatable::Item(parser.parse_item(ForceCollect::Yes).unwrap().unwrap()) + } + Annotatable::TraitItem(_) => |parser| { + Annotatable::TraitItem( + parser.parse_trait_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), + ) + }, + Annotatable::ImplItem(_) => |parser| { + Annotatable::ImplItem( + parser.parse_impl_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), + ) + }, + Annotatable::ForeignItem(_) => |parser| { + Annotatable::ForeignItem( + parser.parse_foreign_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), + ) + }, + Annotatable::Stmt(_) => |parser| { + Annotatable::Stmt(P(parser.parse_stmt(ForceCollect::Yes).unwrap().unwrap())) + }, + Annotatable::Expr(_) => { + |parser| Annotatable::Expr(parser.parse_expr_force_collect().unwrap()) + } + _ => unreachable!(), + }; + let nt = annotatable.into_nonterminal(); let mut orig_tokens = rustc_parse::nt_to_tokenstream( &nt, @@ -173,25 +199,7 @@ impl CfgEval<'_, '_> { let mut parser = rustc_parse::stream_to_parser(&self.cfg.sess.parse_sess, orig_tokens, None); parser.capture_cfg = true; - annotatable = match annotatable { - Annotatable::Item(_) => { - Annotatable::Item(parser.parse_item(ForceCollect::Yes).unwrap().unwrap()) - } - Annotatable::TraitItem(_) => Annotatable::TraitItem( - parser.parse_trait_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), - ), - Annotatable::ImplItem(_) => Annotatable::ImplItem( - parser.parse_impl_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), - ), - Annotatable::ForeignItem(_) => Annotatable::ForeignItem( - parser.parse_foreign_item(ForceCollect::Yes).unwrap().unwrap().unwrap(), - ), - Annotatable::Stmt(_) => { - Annotatable::Stmt(P(parser.parse_stmt(ForceCollect::Yes).unwrap().unwrap())) - } - Annotatable::Expr(_) => Annotatable::Expr(parser.parse_expr_force_collect().unwrap()), - _ => unreachable!(), - }; + annotatable = parse_annotatable_with(&mut parser); // Now that we have our re-parsed `AttrAnnotatedTokenStream`, recursively configuring // our attribute target will correctly the tokens as well.