From 09c807ed829b58a67a4e4612279b5832d969b9fa Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 20 Nov 2023 14:13:52 +1100
Subject: [PATCH] Add two useful comments.

---
 compiler/rustc_driver_impl/src/lib.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 6ee7213a19d8..1a59d72b441e 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -455,6 +455,8 @@ fn run_compiler(
 
             let ongoing_codegen = queries.ongoing_codegen()?;
 
+            // This must run after monomorphization so that all generic types
+            // have been instantiated.
             if sess.opts.unstable_opts.print_type_sizes {
                 sess.code_stats.print_type_sizes();
             }
@@ -469,6 +471,8 @@ fn run_compiler(
             Ok(Some(linker))
         })?;
 
+        // Linking is done outside the `compiler.enter()` so that the
+        // `GlobalCtxt` within `Queries` can be freed as early as possible.
         if let Some(linker) = linker {
             let _timer = sess.timer("link");
             linker.link(sess, codegen_backend)?