Auto merge of #109971 - WaffleLapkin:yeet_ownership, r=Nilstrieb

Yeet `owning_ref`

Based on the discussions from https://github.com/rust-lang/rust/pull/109948

This replaces `owning_ref` with a far simpler & safer abstraction.

Fixes #109974

1 files changed, 7 insertions, 26 deletions

diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs
index e8ee4fb76cc..ef1da85198f 100644
--- a/compiler/rustc_data_structures/src/sync.rs
+++ b/compiler/rustc_data_structures/src/sync.rs
@@ -7,9 +7,6 @@
 //! while the serial versions degenerate straightforwardly to serial execution.
 //! The operations include `join`, `parallel`, `par_iter`, and `par_for_each`.
 //!
-//! `rustc_erase_owner!` erases an `OwningRef` owner into `Erased` for the
-//! serial version and `Erased + Send + Sync` for the parallel version.
-//!
 //! Types
 //! -----
 //! The parallel versions of types provide various kinds of synchronization,
@@ -42,7 +39,7 @@
 //!
 //! [^2] `MTLockRef` is a typedef.
 
-use crate::owning_ref::{Erased, OwningRef};
+use crate::owned_slice::OwnedSlice;
 use std::collections::HashMap;
 use std::hash::{BuildHasher, Hash};
 use std::ops::{Deref, DerefMut};
@@ -57,18 +54,11 @@ mod vec;
 
 cfg_if! {
     if #[cfg(not(parallel_compiler))] {
-        pub auto trait Send {}
-        pub auto trait Sync {}
-
-        impl<T> Send for T {}
-        impl<T> Sync for T {}
+        pub unsafe auto trait Send {}
+        pub unsafe auto trait Sync {}
 
-        #[macro_export]
-        macro_rules! rustc_erase_owner {
-            ($v:expr) => {
-                $v.erase_owner()
-            }
-        }
+        unsafe impl<T> Send for T {}
+        unsafe impl<T> Sync for T {}
 
         use std::ops::Add;
 
@@ -197,7 +187,7 @@ cfg_if! {
             }
         }
 
-        pub type MetadataRef = OwningRef<Box<dyn Erased>, [u8]>;
+        pub type MetadataRef = OwnedSlice;
 
         pub use std::rc::Rc as Lrc;
         pub use std::rc::Weak as Weak;
@@ -380,20 +370,11 @@ cfg_if! {
             });
         }
 
-        pub type MetadataRef = OwningRef<Box<dyn Erased + Send + Sync>, [u8]>;
+        pub type MetadataRef = OwnedSlice;
 
         /// This makes locks panic if they are already held.
         /// It is only useful when you are running in a single thread
         const ERROR_CHECKING: bool = false;
-
-        #[macro_export]
-        macro_rules! rustc_erase_owner {
-            ($v:expr) => {{
-                let v = $v;
-                ::rustc_data_structures::sync::assert_send_val(&v);
-                v.erase_send_sync_owner()
-            }}
-        }
     }
 }