From 64b5b75e65f010d88175fbb98b4396ccede5c32e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= Date: Mon, 15 Feb 2021 00:00:00 +0000 Subject: [PATCH] Use !Sync std::lazy::OnceCell in usefulness checking The `rustc_data_structures::sync::OnceCell` is thread-safe when building a parallel compiler. This is unnecessary for the purposes of pattern usefulness checking. Use `!Sync` `std::lazy::OnceCell` instead. --- compiler/rustc_mir_build/src/thir/pattern/usefulness.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 010fe4fd524d4..38b7e50d78672 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -289,7 +289,6 @@ use super::{PatternFoldable, PatternFolder}; use rustc_data_structures::captures::Captures; use rustc_data_structures::fx::FxHashMap; -use rustc_data_structures::sync::OnceCell; use rustc_arena::TypedArena; use rustc_hir::def_id::DefId; @@ -300,6 +299,7 @@ use rustc_span::Span; use smallvec::{smallvec, SmallVec}; use std::fmt; use std::iter::{FromIterator, IntoIterator}; +use std::lazy::OnceCell; crate struct MatchCheckCtxt<'a, 'tcx> { crate tcx: TyCtxt<'tcx>,