From 809eec5a79e9d29d73d0e49fc6631db04f7db93a Mon Sep 17 00:00:00 2001
From: Mara Bos <m-ou.se@m-ou.se>
Date: Tue, 24 Jan 2023 14:38:57 +0100
Subject: [PATCH] Enable --cfg=parallel_compiler in rustdoc.

---
 src/bootstrap/tool.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/bootstrap/tool.rs b/src/bootstrap/tool.rs
index 9a2100c2fb785..728677ae764f7 100644
--- a/src/bootstrap/tool.rs
+++ b/src/bootstrap/tool.rs
@@ -551,7 +551,7 @@ impl Step for Rustdoc {
             features.push("jemalloc".to_string());
         }
 
-        let cargo = prepare_tool_cargo(
+        let mut cargo = prepare_tool_cargo(
             builder,
             build_compiler,
             Mode::ToolRustc,
@@ -562,6 +562,10 @@ impl Step for Rustdoc {
             features.as_slice(),
         );
 
+        if builder.config.rustc_parallel {
+            cargo.rustflag("--cfg=parallel_compiler");
+        }
+
         builder.info(&format!(
             "Building rustdoc for stage{} ({})",
             target_compiler.stage, target_compiler.host