From 43bb31b9540a439dcca65f47b8644eafe4a42e2d Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Mon, 12 Jul 2021 22:19:25 +0200
Subject: Allow to create definitions inside the query system.

---
 compiler/rustc_data_structures/src/lib.rs  |  1 +
 compiler/rustc_data_structures/src/sync.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

(limited to 'compiler/rustc_data_structures/src')

diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 390a44d3f33..0a2d2b40709 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -10,6 +10,7 @@
 #![feature(array_windows)]
 #![feature(associated_type_bounds)]
 #![feature(auto_traits)]
+#![feature(cell_leak)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]
 #![feature(let_else)]
diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs
index 4437c0b1b69..cf0940df9e4 100644
--- a/compiler/rustc_data_structures/src/sync.rs
+++ b/compiler/rustc_data_structures/src/sync.rs
@@ -539,6 +539,33 @@ impl<T> RwLock<T> {
     pub fn borrow_mut(&self) -> WriteGuard<'_, T> {
         self.write()
     }
+
+    #[cfg(not(parallel_compiler))]
+    #[inline(always)]
+    pub fn clone_guard<'a>(rg: &ReadGuard<'a, T>) -> ReadGuard<'a, T> {
+        ReadGuard::clone(rg)
+    }
+
+    #[cfg(parallel_compiler)]
+    #[inline(always)]
+    pub fn clone_guard<'a>(rg: &ReadGuard<'a, T>) -> ReadGuard<'a, T> {
+        ReadGuard::rwlock(&rg).read()
+    }
+
+    #[cfg(not(parallel_compiler))]
+    #[inline(always)]
+    pub fn leak(&self) -> &T {
+        ReadGuard::leak(self.read())
+    }
+
+    #[cfg(parallel_compiler)]
+    #[inline(always)]
+    pub fn leak(&self) -> &T {
+        let guard = self.read();
+        let ret = unsafe { &*(&*guard as *const T) };
+        std::mem::forget(guard);
+        ret
+    }
 }
 
 // FIXME: Probably a bad idea
-- 
cgit 1.4.1-3-g733a5