Auto merge of #124895 - obeis:static-mut-hidden-ref, r=compiler-errors

Disallow hidden references to mutable static

Closes #123060

Tracking:
- rust-lang/rust#123758

tests/ui/checked_unwrap/simple_conditionals.stderr

@@ -236,5 +236,16 @@ LL |     if result.is_ok() {
 LL |         result.as_mut().unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 25 previous errors
+error: creating a shared reference to mutable static is discouraged
+  --> tests/ui/checked_unwrap/simple_conditionals.rs:174:12
+   |
+LL |         if X.is_some() {
+   |            ^^^^^^^^^^^ shared reference to mutable static
+   |
+   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/static-mut-references.html>
+   = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
+   = note: `-D static-mut-refs` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(static_mut_refs)]`
+
+error: aborting due to 26 previous errors
 

tests/ui/multiple_unsafe_ops_per_block.rs

@@ -4,6 +4,7 @@
 #![allow(deref_nullptr)]
 #![allow(clippy::unnecessary_operation)]
 #![allow(dropping_copy_types)]
+#![allow(clippy::assign_op_pattern)]
 #![warn(clippy::multiple_unsafe_ops_per_block)]
 
 extern crate proc_macros;

tests/ui/multiple_unsafe_ops_per_block.stderr

@@ -1,5 +1,5 @@
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:37:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:38:5
    |
 LL | /     unsafe {
 LL | |         STATIC += 1;
@@ -8,20 +8,20 @@ LL | |     }
    | |_____^
    |
 note: modification of a mutable static occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:38:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:39:9
    |
 LL |         STATIC += 1;
    |         ^^^^^^^^^^^
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:39:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:40:9
    |
 LL |         not_very_safe();
    |         ^^^^^^^^^^^^^^^
    = note: `-D clippy::multiple-unsafe-ops-per-block` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::multiple_unsafe_ops_per_block)]`
 
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:46:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:47:5
    |
 LL | /     unsafe {
 LL | |         drop(u.u);
@@ -30,18 +30,18 @@ LL | |     }
    | |_____^
    |
 note: union field access occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:47:14
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:48:14
    |
 LL |         drop(u.u);
    |              ^^^
 note: raw pointer dereference occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:48:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:49:9
    |
 LL |         *raw_ptr();
    |         ^^^^^^^^^^
 
 error: this `unsafe` block contains 3 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:53:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:54:5
    |
 LL | /     unsafe {
 LL | |         asm!("nop");
@@ -51,23 +51,23 @@ LL | |     }
    | |_____^
    |
 note: inline assembly used here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:54:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:55:9
    |
 LL |         asm!("nop");
    |         ^^^^^^^^^^^
 note: unsafe method call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:55:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:56:9
    |
 LL |         sample.not_very_safe();
    |         ^^^^^^^^^^^^^^^^^^^^^^
 note: modification of a mutable static occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:56:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:57:9
    |
 LL |         STATIC = 0;
    |         ^^^^^^^^^^
 
 error: this `unsafe` block contains 6 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:62:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:63:5
    |
 LL | /     unsafe {
 LL | |         drop(u.u);
@@ -79,55 +79,55 @@ LL | |     }
    | |_____^
    |
 note: union field access occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:63:14
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:64:14
    |
 LL |         drop(u.u);
    |              ^^^
 note: access of a mutable static occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:64:14
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:65:14
    |
 LL |         drop(STATIC);
    |              ^^^^^^
 note: unsafe method call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:65:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:66:9
    |
 LL |         sample.not_very_safe();
    |         ^^^^^^^^^^^^^^^^^^^^^^
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:66:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:67:9
    |
 LL |         not_very_safe();
    |         ^^^^^^^^^^^^^^^
 note: raw pointer dereference occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:67:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:68:9
    |
 LL |         *raw_ptr();
    |         ^^^^^^^^^^
 note: inline assembly used here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:68:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:69:9
    |
 LL |         asm!("nop");
    |         ^^^^^^^^^^^
 
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:106:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:107:5
    |
 LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:106:14
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:107:14
    |
 LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: raw pointer dereference occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:106:39
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:107:39
    |
 LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
    |                                       ^^^^^^^^^^^^^^^^^^
 
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:124:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:125:5
    |
 LL | /     unsafe {
 LL | |         x();
@@ -136,18 +136,18 @@ LL | |     }
    | |_____^
    |
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:125:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:126:9
    |
 LL |         x();
    |         ^^^
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:126:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:127:9
    |
 LL |         x();
    |         ^^^
 
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:135:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:136:9
    |
 LL | /         unsafe {
 LL | |             T::X();
@@ -156,18 +156,18 @@ LL | |         }
    | |_________^
    |
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:136:13
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:137:13
    |
 LL |             T::X();
    |             ^^^^^^
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:137:13
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:138:13
    |
 LL |             T::X();
    |             ^^^^^^
 
 error: this `unsafe` block contains 2 unsafe operations, expected only one
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:145:5
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:146:5
    |
 LL | /     unsafe {
 LL | |         x.0();
@@ -176,12 +176,12 @@ LL | |     }
    | |_____^
    |
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:146:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:147:9
    |
 LL |         x.0();
    |         ^^^^^
 note: unsafe function call occurs here
-  --> tests/ui/multiple_unsafe_ops_per_block.rs:147:9
+  --> tests/ui/multiple_unsafe_ops_per_block.rs:148:9
    |
 LL |         x.0();
    |         ^^^^^

tests/ui/must_use_candidates.fixed

@@ -1,5 +1,10 @@
 #![feature(never_type)]
-#![allow(unused_mut, clippy::redundant_allocation, clippy::needless_pass_by_ref_mut)]
+#![allow(
+    unused_mut,
+    clippy::redundant_allocation,
+    clippy::needless_pass_by_ref_mut,
+    static_mut_refs
+)]
 #![warn(clippy::must_use_candidate)]
 use std::rc::Rc;
 use std::sync::atomic::{AtomicBool, Ordering};

tests/ui/must_use_candidates.rs

@@ -1,5 +1,10 @@
 #![feature(never_type)]
-#![allow(unused_mut, clippy::redundant_allocation, clippy::needless_pass_by_ref_mut)]
+#![allow(
+    unused_mut,
+    clippy::redundant_allocation,
+    clippy::needless_pass_by_ref_mut,
+    static_mut_refs
+)]
 #![warn(clippy::must_use_candidate)]
 use std::rc::Rc;
 use std::sync::atomic::{AtomicBool, Ordering};

tests/ui/must_use_candidates.stderr

@@ -1,5 +1,5 @@
 error: this function could have a `#[must_use]` attribute
-  --> tests/ui/must_use_candidates.rs:11:1
+  --> tests/ui/must_use_candidates.rs:16:1
    |
 LL | pub fn pure(i: u8) -> u8 {
    | ^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn pure(i: u8) -> u8`
@@ -8,25 +8,25 @@ LL | pub fn pure(i: u8) -> u8 {
    = help: to override `-D warnings` add `#[allow(clippy::must_use_candidate)]`
 
 error: this method could have a `#[must_use]` attribute
-  --> tests/ui/must_use_candidates.rs:16:5
+  --> tests/ui/must_use_candidates.rs:21:5
    |
 LL |     pub fn inherent_pure(&self) -> u8 {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn inherent_pure(&self) -> u8`
 
 error: this function could have a `#[must_use]` attribute
-  --> tests/ui/must_use_candidates.rs:47:1
+  --> tests/ui/must_use_candidates.rs:52:1
    |
 LL | pub fn with_marker(_d: std::marker::PhantomData<&mut u32>) -> bool {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn with_marker(_d: std::marker::PhantomData<&mut u32>) -> bool`
 
 error: this function could have a `#[must_use]` attribute
-  --> tests/ui/must_use_candidates.rs:59:1
+  --> tests/ui/must_use_candidates.rs:64:1
    |
 LL | pub fn rcd(_x: Rc<u32>) -> bool {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn rcd(_x: Rc<u32>) -> bool`
 
 error: this function could have a `#[must_use]` attribute
-  --> tests/ui/must_use_candidates.rs:67:1
+  --> tests/ui/must_use_candidates.rs:72:1
    |
 LL | pub fn arcd(_x: Arc<u32>) -> bool {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn arcd(_x: Arc<u32>) -> bool`

tests/ui/redundant_static_lifetimes.fixed

@@ -1,4 +1,6 @@
 #![allow(unused)]
+// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
+#![allow(static_mut_refs)]
 
 #[derive(Debug)]
 struct Foo;

tests/ui/redundant_static_lifetimes.rs

@@ -1,4 +1,6 @@
 #![allow(unused)]
+// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
+#![allow(static_mut_refs)]
 
 #[derive(Debug)]
 struct Foo;