From 7a209bb7a55580076ce77ae859330875f6e2f18c Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Tue, 12 Oct 2021 20:53:29 +0200
Subject: [PATCH] Justify untracked access.

---
 compiler/rustc_middle/src/hir/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index 1648d0d3ac17..95d7273b17b4 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -71,6 +71,7 @@ pub fn provide(providers: &mut Providers) {
     };
     providers.hir_owner_nodes = |tcx, id| tcx.hir_crate(()).owners[id].as_ref().map(|i| &i.nodes);
     providers.hir_owner_parent = |tcx, id| {
+        // Accessing the def_key is ok since its value is hashed as part of `id`'s DefPathHash.
         let parent = tcx.untracked_resolutions.definitions.def_key(id).parent;
         let parent = parent.map_or(CRATE_HIR_ID, |local_def_index| {
             let def_id = LocalDefId { local_def_index };