From b4a46457581e9c777af8d31a9e1cd145d8c1be31 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 15 Apr 2024 17:45:04 +0200
Subject: [PATCH] static_mut_refs: use raw pointers to remove the remaining
FIXME
---
.../example/mini_core_hello_world.rs | 15 +++++++++++----
.../example/mini_core_hello_world.rs | 6 ++----
library/std/src/sys/thread_local/static_local.rs | 5 ++---
3 files changed, 15 insertions(+), 11 deletions(-)
diff --git a/compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs b/compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs
index 8b0b9123ac7df..efa4be7e15ac3 100644
--- a/compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs
+++ b/compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs
@@ -1,4 +1,13 @@
-#![feature(no_core, lang_items, never_type, linkage, extern_types, thread_local, repr_simd)]
+#![feature(
+ no_core,
+ lang_items,
+ never_type,
+ linkage,
+ extern_types,
+ thread_local,
+ repr_simd,
+ raw_ref_op
+)]
#![no_core]
#![allow(dead_code, non_camel_case_types, internal_features)]
@@ -112,9 +121,7 @@ fn start<T: Termination + 'static>(
static mut NUM: u8 = 6 * 7;
-// FIXME: Use `SyncUnsafeCell` instead of allowing `static_mut_refs` lint
-#[allow(static_mut_refs)]
-static NUM_REF: &'static u8 = unsafe { &NUM };
+static NUM_REF: &'static u8 = unsafe { &*&raw const NUM };
unsafe fn zeroed<T>() -> T {
let mut uninit = MaybeUninit { uninit: () };
diff --git a/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs b/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
index add77880716c8..5a7ddc4cd7fa5 100644
--- a/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
+++ b/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
@@ -2,7 +2,7 @@
#![feature(
no_core, unboxed_closures, start, lang_items, never_type, linkage,
- extern_types, thread_local
+ extern_types, thread_local, raw_ref_op
)]
#![no_core]
#![allow(dead_code, internal_features, non_camel_case_types)]
@@ -99,9 +99,7 @@ fn start<T: Termination + 'static>(
static mut NUM: u8 = 6 * 7;
-// FIXME: Use `SyncUnsafeCell` instead of allowing `static_mut_refs` lint
-#[allow(static_mut_refs)]
-static NUM_REF: &'static u8 = unsafe { &NUM };
+static NUM_REF: &'static u8 = unsafe { &* &raw const NUM };
macro_rules! assert {
($e:expr) => {
diff --git a/library/std/src/sys/thread_local/static_local.rs b/library/std/src/sys/thread_local/static_local.rs
index 206e62bb5e2c8..162c3fbd97a0e 100644
--- a/library/std/src/sys/thread_local/static_local.rs
+++ b/library/std/src/sys/thread_local/static_local.rs
@@ -11,8 +11,6 @@ pub macro thread_local_inner {
(@key $t:ty, const $init:expr) => {{
#[inline] // see comments below
#[deny(unsafe_op_in_unsafe_fn)]
- // FIXME: Use `SyncUnsafeCell` instead of allowing `static_mut_refs` lint
- #[allow(static_mut_refs)]
unsafe fn __getit(
_init: $crate::option::Option<&mut $crate::option::Option<$t>>,
) -> $crate::option::Option<&'static $t> {
@@ -25,7 +23,8 @@ pub macro thread_local_inner {
// FIXME(#84224) this should come after the `target_thread_local`
// block.
static mut VAL: $t = INIT_EXPR;
- unsafe { $crate::option::Option::Some(&VAL) }
+ // SAFETY: we only ever create shared references, so there's no mutable aliasing.
+ unsafe { $crate::option::Option::Some(&*$crate::ptr::addr_of!(VAL)) }
}
unsafe {