From 1cec923fbb9f5a71ff9664e9c8eba9d40ed02319 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Thu, 23 Mar 2023 20:44:48 +0400
Subject: [PATCH] rustc_metadata: Freeze cstore after the full crate list is
 queried

---
 compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 0d54f292636..3a50d7c9363 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -490,6 +490,9 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
                 .alloc_slice(&CStore::from_tcx(tcx).crate_dependencies_in_postorder(LOCAL_CRATE))
         },
         crates: |tcx, ()| {
+            // The list of loaded crates is now frozen in query cache,
+            // so make sure cstore is not mutably accessed from here on.
+            tcx.untracked().cstore.leak();
             tcx.arena.alloc_from_iter(CStore::from_tcx(tcx).iter_crate_data().map(|(cnum, _)| cnum))
         },
         ..*providers