Added deny(const_eval_mutable_ptr_in_final_value) attribute to all …

…tests that were expecting the hard error for it.

I attempted to do this in a manner that preserved the line numbers to reduce the
review effort on the resulting diff, but we still have to deal with the
ramifications of how a future-incompat lint behaves compared to a hard-error (in
terms of its impact on the diagnostic output).

tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.rs

@@ -1,9 +1,11 @@
 #![feature(core_intrinsics)]
 #![feature(const_heap)]
 #![feature(const_mut_refs)]
+#![deny(const_eval_mutable_ptr_in_final_value)]
 use std::intrinsics;
 
 const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 };
 //~^ error: mutable pointer in final value of constant
+//~| WARNING this was previously accepted by the compiler
 
 fn main() {}

tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.stderr

@@ -1,8 +1,31 @@
 error: encountered mutable pointer in final value of constant
-  --> $DIR/alloc_intrinsic_untyped.rs:6:1
+  --> $DIR/alloc_intrinsic_untyped.rs:7:1
    |
 LL | const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 };
    | ^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/alloc_intrinsic_untyped.rs:4:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 1 previous error
 
+Future incompatibility report: Future breakage diagnostic:
+error: encountered mutable pointer in final value of constant
+  --> $DIR/alloc_intrinsic_untyped.rs:7:1
+   |
+LL | const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 };
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/alloc_intrinsic_untyped.rs:4:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+

tests/ui/consts/miri_unleashed/mutable_references.rs

@@ -1,29 +1,37 @@
 //@ compile-flags: -Zunleash-the-miri-inside-of-you
-
+#![deny(const_eval_mutable_ptr_in_final_value)]
 use std::cell::UnsafeCell;
 
 // a test demonstrating what things we could allow with a smarter const qualification
 
 static FOO: &&mut u32 = &&mut 42;
 //~^ ERROR encountered mutable pointer in final value of static
+//~| WARNING this was previously accepted by the compiler
+//~| ERROR it is undefined behavior to use this value
 
 static BAR: &mut () = &mut ();
 //~^ ERROR encountered mutable pointer in final value of static
+//~| WARNING this was previously accepted by the compiler
 
 struct Foo<T>(T);
 
 static BOO: &mut Foo<()> = &mut Foo(());
 //~^ ERROR encountered mutable pointer in final value of static
+//~| WARNING this was previously accepted by the compiler
 
 struct Meh {
     x: &'static UnsafeCell<i32>,
 }
 unsafe impl Sync for Meh {}
 static MEH: Meh = Meh { x: &UnsafeCell::new(42) };
 //~^ ERROR encountered mutable pointer in final value of static
+//~| WARNING this was previously accepted by the compiler
+//~| ERROR it is undefined behavior to use this value
 
 static OH_YES: &mut i32 = &mut 42;
 //~^ ERROR encountered mutable pointer in final value of static
+//~| WARNING this was previously accepted by the compiler
+//~| ERROR it is undefined behavior to use this value
 
 fn main() {
     unsafe {

tests/ui/consts/miri_unleashed/mutable_references.stderr

@@ -3,33 +3,86 @@ error: encountered mutable pointer in final value of static
    |
 LL | static FOO: &&mut u32 = &&mut 42;
    | ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/mutable_references.rs:7:1
+   |
+LL | static FOO: &&mut u32 = &&mut 42;
+   | ^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .<deref>: encountered mutable reference or box pointing to read-only memory
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: 8, align: 8) {
+               ╾ALLOC0<imm>╼                         │ ╾──────╼
+           }
 
 error: encountered mutable pointer in final value of static
-  --> $DIR/mutable_references.rs:10:1
+  --> $DIR/mutable_references.rs:12:1
    |
 LL | static BAR: &mut () = &mut ();
    | ^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
 
 error: encountered mutable pointer in final value of static
-  --> $DIR/mutable_references.rs:15:1
+  --> $DIR/mutable_references.rs:18:1
    |
 LL | static BOO: &mut Foo<()> = &mut Foo(());
    | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
 
 error: encountered mutable pointer in final value of static
-  --> $DIR/mutable_references.rs:22:1
+  --> $DIR/mutable_references.rs:26:1
    |
 LL | static MEH: Meh = Meh { x: &UnsafeCell::new(42) };
    | ^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/mutable_references.rs:26:1
+   |
+LL | static MEH: Meh = Meh { x: &UnsafeCell::new(42) };
+   | ^^^^^^^^^^^^^^^ constructing invalid value at .x.<deref>: encountered `UnsafeCell` in read-only memory
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: 8, align: 8) {
+               ╾ALLOC1╼                         │ ╾──────╼
+           }
 
 error: encountered mutable pointer in final value of static
-  --> $DIR/mutable_references.rs:25:1
+  --> $DIR/mutable_references.rs:31:1
    |
 LL | static OH_YES: &mut i32 = &mut 42;
    | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/mutable_references.rs:31:1
+   |
+LL | static OH_YES: &mut i32 = &mut 42;
+   | ^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered mutable reference or box pointing to read-only memory
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: 8, align: 8) {
+               ╾ALLOC2╼                         │ ╾──────╼
+           }
 
 error[E0594]: cannot assign to `*OH_YES`, as `OH_YES` is an immutable static item
-  --> $DIR/mutable_references.rs:32:5
+  --> $DIR/mutable_references.rs:40:5
    |
 LL |     *OH_YES = 99;
    |     ^^^^^^^^^^^^ cannot assign
@@ -42,26 +95,102 @@ help: skipping check that does not even have a feature gate
 LL | static FOO: &&mut u32 = &&mut 42;
    |                          ^^^^^^^
 help: skipping check that does not even have a feature gate
-  --> $DIR/mutable_references.rs:10:23
+  --> $DIR/mutable_references.rs:12:23
    |
 LL | static BAR: &mut () = &mut ();
    |                       ^^^^^^^
 help: skipping check that does not even have a feature gate
-  --> $DIR/mutable_references.rs:15:28
+  --> $DIR/mutable_references.rs:18:28
    |
 LL | static BOO: &mut Foo<()> = &mut Foo(());
    |                            ^^^^^^^^^^^^
 help: skipping check that does not even have a feature gate
-  --> $DIR/mutable_references.rs:22:28
+  --> $DIR/mutable_references.rs:26:28
    |
 LL | static MEH: Meh = Meh { x: &UnsafeCell::new(42) };
    |                            ^^^^^^^^^^^^^^^^^^^^
 help: skipping check that does not even have a feature gate
-  --> $DIR/mutable_references.rs:25:27
+  --> $DIR/mutable_references.rs:31:27
    |
 LL | static OH_YES: &mut i32 = &mut 42;
    |                           ^^^^^^^
 
-error: aborting due to 6 previous errors; 1 warning emitted
+error: aborting due to 9 previous errors; 1 warning emitted
+
+Some errors have detailed explanations: E0080, E0594.
+For more information about an error, try `rustc --explain E0080`.
+Future incompatibility report: Future breakage diagnostic:
+error: encountered mutable pointer in final value of static
+  --> $DIR/mutable_references.rs:7:1
+   |
+LL | static FOO: &&mut u32 = &&mut 42;
+   | ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Future breakage diagnostic:
+error: encountered mutable pointer in final value of static
+  --> $DIR/mutable_references.rs:12:1
+   |
+LL | static BAR: &mut () = &mut ();
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Future breakage diagnostic:
+error: encountered mutable pointer in final value of static
+  --> $DIR/mutable_references.rs:18:1
+   |
+LL | static BOO: &mut Foo<()> = &mut Foo(());
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Future breakage diagnostic:
+error: encountered mutable pointer in final value of static
+  --> $DIR/mutable_references.rs:26:1
+   |
+LL | static MEH: Meh = Meh { x: &UnsafeCell::new(42) };
+   | ^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Future breakage diagnostic:
+error: encountered mutable pointer in final value of static
+  --> $DIR/mutable_references.rs:31:1
+   |
+LL | static OH_YES: &mut i32 = &mut 42;
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #122153 <https://github.com/rust-lang/rust/issues/122153>
+note: the lint level is defined here
+  --> $DIR/mutable_references.rs:2:9
+   |
+LL | #![deny(const_eval_mutable_ptr_in_final_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-For more information about this error, try `rustc --explain E0594`.

tests/ui/consts/miri_unleashed/mutable_references_err.rs

@@ -2,7 +2,7 @@
 //@ normalize-stderr-test "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
 //@ normalize-stderr-test "([0-9a-f][0-9a-f] |╾─*ALLOC[0-9]+(\+[a-z0-9]+)?(<imm>)?─*╼ )+ *│.*" -> "HEX_DUMP"
 #![allow(invalid_reference_casting, static_mut_refs)]
-
+#![deny(const_eval_mutable_ptr_in_final_value)]
 use std::cell::UnsafeCell;
 use std::sync::atomic::*;
 
@@ -17,6 +17,8 @@ unsafe impl Sync for Meh {}
 // all allocs interned here will be marked immutable.
 const MUH: Meh = Meh {
     //~^ ERROR encountered mutable pointer in final value of constant
+    //~| WARNING this was previously accepted by the compiler
+    //~| ERROR: it is undefined behavior to use this value
     x: &UnsafeCell::new(42),
 };
 
@@ -28,14 +30,19 @@ unsafe impl Sync for Synced {}
 // Make sure we also catch this behind a type-erased `dyn Trait` reference.
 const SNEAKY: &dyn Sync = &Synced { x: UnsafeCell::new(42) };
 //~^ ERROR: mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+//~| ERROR it is undefined behavior to use this value
 
 // Make sure we also catch mutable references in values that shouldn't have them.
 static mut FOO: i32 = 0;
 const SUBTLE: &mut i32 = unsafe { &mut FOO };
 //~^ ERROR: it is undefined behavior to use this value
 //~| static
+
 const BLUNT: &mut i32 = &mut 42;
 //~^ ERROR: mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+//~| ERROR it is undefined behavior to use this value
 
 // Check for mutable references to read-only memory.
 static READONLY: i32 = 0;
@@ -56,10 +63,15 @@ const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
 
 const POINTS_TO_MUTABLE_INNER: *const i32 = &mut 42 as *mut _ as *const _;
 //~^ ERROR: mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+
 const POINTS_TO_MUTABLE_INNER2: *const i32 = &mut 42 as *const _;
 //~^ ERROR: mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+
 const INTERIOR_MUTABLE_BEHIND_RAW: *mut i32 = &UnsafeCell::new(42) as *const _ as *mut _;
 //~^ ERROR: mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
 
 struct SyncPtr<T> {
     x: *const T,
@@ -72,10 +84,15 @@ unsafe impl<T> Sync for SyncPtr<T> {}
 // (Also see `static-no-inner-mut` for similar tests on `static`.)
 const RAW_SYNC: SyncPtr<AtomicI32> = SyncPtr { x: &AtomicI32::new(42) };
 //~^ ERROR mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+
 const RAW_MUT_CAST: SyncPtr<i32> = SyncPtr { x: &mut 42 as *mut _ as *const _ };
 //~^ ERROR mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
+
 const RAW_MUT_COERCE: SyncPtr<i32> = SyncPtr { x: &mut 0 };
 //~^ ERROR mutable pointer in final value
+//~| WARNING this was previously accepted by the compiler
 
 fn main() {
     unsafe {