Update lint_levels

src/librustc/arena.rs

@@ -78,6 +78,7 @@ macro_rules! arena_types {
                 >,
             [few] resolve_lifetimes: rustc::middle::resolve_lifetime::ResolveLifetimes,
             [decode] generic_predicates: rustc::ty::GenericPredicates<'tcx>,
+            [few] lint_levels: rustc::lint::LintLevelMap,
         ], $tcx);
     )
 }

src/librustc/lint/mod.rs

@@ -21,7 +21,7 @@
 pub use self::Level::*;
 pub use self::LintSource::*;
 
-use rustc_data_structures::sync::{self, Lrc};
+use rustc_data_structures::sync;
 
 use crate::hir::def_id::{CrateNum, LOCAL_CRATE};
 use crate::hir::intravisit;
@@ -767,7 +767,7 @@ pub fn maybe_lint_level_root(tcx: TyCtxt<'_, '_, '_>, id: hir::HirId) -> bool {
 }
 
 fn lint_levels<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, cnum: CrateNum)
-    -> Lrc<LintLevelMap>
+    -> &'tcx LintLevelMap
 {
     assert_eq!(cnum, LOCAL_CRATE);
     let mut builder = LintLevelMapBuilder {
@@ -784,7 +784,7 @@ fn lint_levels<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, cnum: CrateNum)
     intravisit::walk_crate(&mut builder, krate);
     builder.levels.pop(push);
 
-    Lrc::new(builder.levels.build_map())
+    tcx.arena.alloc(builder.levels.build_map())
 }
 
 struct LintLevelMapBuilder<'a, 'tcx: 'a> {

src/librustc/query/mod.rs

@@ -67,7 +67,7 @@ rustc_queries! {
             desc { "looking up the native libraries of a linked crate" }
         }
 
-        query lint_levels(_: CrateNum) -> Lrc<lint::LintLevelMap> {
+        query lint_levels(_: CrateNum) -> &'tcx lint::LintLevelMap {
             eval_always
             desc { "computing the lint levels for items in this crate" }
         }