rebase

10 files changed, 118 insertions, 44 deletions

diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
index f8497702832..4ac3d2eaa0c 100644
--- a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
+++ b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -703,7 +703,8 @@ fn push_const_param<'tcx>(tcx: TyCtxt<'tcx>, ct: ty::Const<'tcx>, output: &mut S
                 // but we get a deterministic, virtually unique value for the constant.
                 let hcx = &mut tcx.create_stable_hashing_context();
                 let mut hasher = StableHasher::new();
-                hcx.while_hashing_spans(false, |hcx| ct.kind().hash_stable(hcx, &mut hasher));
+                let ct = ct.eval(tcx, ty::ParamEnv::reveal_all());
+                hcx.while_hashing_spans(false, |hcx| ct.to_valtree().hash_stable(hcx, &mut hasher));
                 // Let's only emit 64 bits of the hash value. That should be plenty for
                 // avoiding collisions and will make the emitted type names shorter.
                 let hash: u64 = hasher.finish();
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index a53583d8673..b386ed68dd2 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -42,8 +42,8 @@ use rustc_query_system::ich::StableHashingContext;
 use rustc_session::cstore::CrateStoreDyn;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::Span;
-pub use subst::*;
 use rustc_target::abi::{Align, VariantIdx};
+pub use subst::*;
 pub use vtable::*;
 
 use std::fmt::Debug;
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index 8d14a37676d..94c71bbf56d 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -3,8 +3,9 @@ pub(crate) use crate::build::expr::as_constant::lit_to_mir_constant;
 use crate::build::expr::as_place::PlaceBuilder;
 use crate::build::scope::DropKind;
 use crate::thir::pattern::pat_from_hir;
-use rustc_data_structures::fx::FxHashMap;
 use rustc_apfloat::ieee::{Double, Single};
+use rustc_apfloat::Float;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
diff --git a/src/test/ui/associated-consts/defaults-cyclic-fail.stderr b/src/test/ui/associated-consts/defaults-cyclic-fail.stderr
index 550897790e9..c4cd9c2a49f 100644
--- a/src/test/ui/associated-consts/defaults-cyclic-fail.stderr
+++ b/src/test/ui/associated-consts/defaults-cyclic-fail.stderr
@@ -11,10 +11,10 @@ LL |     const B: u8 = Self::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^
    = note: ...which again requires const-evaluating + checking `Tr::A`, completing the cycle
 note: cycle used when const-evaluating + checking `main::promoted[1]`
-  --> $DIR/defaults-cyclic-fail.rs:14:1
+  --> $DIR/defaults-cyclic-fail.rs:16:16
    |
-LL | fn main() {
-   | ^^^^^^^^^
+LL |     assert_eq!(<() as Tr>::A, 0);
+   |                ^^^^^^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
index 8c85fadf600..b4dc730d863 100644
--- a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
+++ b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
@@ -1,8 +1,8 @@
 error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 13:2>::BAR`
-  --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:5
+  --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:22
    |
 LL |     const BAR: u32 = IMPL_REF_BAR;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                      ^^^^^^^^^^^^
    |
 note: ...which requires const-evaluating + checking `IMPL_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:7:1
diff --git a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
index 251a69aeaba..97ede6ad388 100644
--- a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
+++ b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
@@ -1,8 +1,8 @@
 error[E0391]: cycle detected when elaborating drops for `FooDefault::BAR`
-  --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:5
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:22
    |
 LL |     const BAR: u32 = DEFAULT_REF_BAR;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                      ^^^^^^^^^^^^^^^
    |
 note: ...which requires const-evaluating + checking `DEFAULT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:11:1
diff --git a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
index 45e911d0029..bd97c31229e 100644
--- a/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
+++ b/src/test/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
@@ -1,8 +1,8 @@
 error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 13:2>::BAR`
-  --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:5
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:22
    |
 LL |     const BAR: u32 = TRAIT_REF_BAR;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                      ^^^^^^^^^^^^^
    |
 note: ...which requires const-evaluating + checking `TRAIT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:7:1
diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.32bit.stderr b/src/test/ui/consts/const-eval/ub-wide-ptr.32bit.stderr
index a5e3d078bd0..a78cff11589 100644
--- a/src/test/ui/consts/const-eval/ub-wide-ptr.32bit.stderr
+++ b/src/test/ui/consts/const-eval/ub-wide-ptr.32bit.stderr
@@ -149,8 +149,19 @@ LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
                ╾─allocN─╼                                     │ ╾──╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:87:40
+   |
+LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
+   | ---------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                        |
+   |                                        referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:93:1
+  --> $DIR/ub-wide-ptr.rs:95:1
    |
 LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.0: encountered 0x03, but expected a boolean
@@ -160,8 +171,19 @@ LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3
                ╾allocN─╼                                     │ ╾──╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:95:42
+   |
+LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
+   | -----------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                          |
+   |                                          referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:96:1
+  --> $DIR/ub-wide-ptr.rs:100:1
    |
 LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.1[0]: encountered 0x03, but expected a boolean
@@ -171,8 +193,19 @@ LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::tran
                ╾allocN─╼                                     │ ╾──╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:100:42
+   |
+LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
+   | -----------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                          |
+   |                                          referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:103:1
+  --> $DIR/ub-wide-ptr.rs:109:1
    |
 LL | / const RAW_SLICE_LENGTH_UNINIT: *const [u8] = unsafe {
 LL | |
@@ -187,7 +220,7 @@ LL | | };
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:111:1
+  --> $DIR/ub-wide-ptr.rs:117:1
    |
 LL | const TRAIT_OBJ_SHORT_VTABLE_1: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u8))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered too small vtable
@@ -198,7 +231,7 @@ LL | const TRAIT_OBJ_SHORT_VTABLE_1: W<&dyn Trait> = unsafe { mem::transmute(W((
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:114:1
+  --> $DIR/ub-wide-ptr.rs:120:1
    |
 LL | const TRAIT_OBJ_SHORT_VTABLE_2: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u64))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered too small vtable
@@ -209,7 +242,7 @@ LL | const TRAIT_OBJ_SHORT_VTABLE_2: W<&dyn Trait> = unsafe { mem::transmute(W((
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:117:1
+  --> $DIR/ub-wide-ptr.rs:123:1
    |
 LL | const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, 4usize))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered dangling vtable pointer in wide pointer
@@ -220,7 +253,7 @@ LL | const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:119:1
+  --> $DIR/ub-wide-ptr.rs:125:1
    |
 LL | const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92u8, &[0u8; 128])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered unaligned vtable pointer in wide pointer
@@ -231,7 +264,7 @@ LL | const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:121:1
+  --> $DIR/ub-wide-ptr.rs:127:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92u8, &[0usize; 8])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -242,7 +275,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:123:1
+  --> $DIR/ub-wide-ptr.rs:129:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u8, &[1usize; 8])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -253,7 +286,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:125:1
+  --> $DIR/ub-wide-ptr.rs:131:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &[&42u8; 8]))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -264,7 +297,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::trans
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:129:1
+  --> $DIR/ub-wide-ptr.rs:135:1
    |
 LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, &bool>(&3u8) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.<dyn-downcast>: encountered 0x03, but expected a boolean
@@ -275,7 +308,7 @@ LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_,
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:133:1
+  --> $DIR/ub-wide-ptr.rs:139:1
    |
 LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling vtable pointer in wide pointer
@@ -286,7 +319,7 @@ LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:135:1
+  --> $DIR/ub-wide-ptr.rs:141:1
    |
 LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered too small vtable
@@ -297,17 +330,17 @@ LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transm
            }
 
 error[E0080]: could not evaluate static initializer
-  --> $DIR/ub-wide-ptr.rs:141:5
+  --> $DIR/ub-wide-ptr.rs:147:5
    |
 LL |     mem::transmute::<_, &dyn Trait>((&92u8, 0usize))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: null pointer is not a valid pointer
 
 error[E0080]: could not evaluate static initializer
-  --> $DIR/ub-wide-ptr.rs:145:5
+  --> $DIR/ub-wide-ptr.rs:151:5
    |
 LL |     mem::transmute::<_, &dyn Trait>((&92u8, &3u64))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: allocN has size N, so pointer to 12 bytes starting at offset N is out-of-bounds
 
-error: aborting due to 29 previous errors
+error: aborting due to 32 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.64bit.stderr b/src/test/ui/consts/const-eval/ub-wide-ptr.64bit.stderr
index a3ba62ca87b..69a61d9caed 100644
--- a/src/test/ui/consts/const-eval/ub-wide-ptr.64bit.stderr
+++ b/src/test/ui/consts/const-eval/ub-wide-ptr.64bit.stderr
@@ -149,8 +149,19 @@ LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
                ╾───────allocN───────╼                         │ ╾──────╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:87:40
+   |
+LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
+   | ---------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                        |
+   |                                        referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:93:1
+  --> $DIR/ub-wide-ptr.rs:95:1
    |
 LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.0: encountered 0x03, but expected a boolean
@@ -160,8 +171,19 @@ LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3
                ╾──────allocN───────╼                         │ ╾──────╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:95:42
+   |
+LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
+   | -----------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                          |
+   |                                          referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:96:1
+  --> $DIR/ub-wide-ptr.rs:100:1
    |
 LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.1[0]: encountered 0x03, but expected a boolean
@@ -171,8 +193,19 @@ LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::tran
                ╾──────allocN───────╼                         │ ╾──────╼
            }
 
+error: any use of this value will cause an error
+  --> $DIR/ub-wide-ptr.rs:100:42
+   |
+LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
+   | -----------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |                                          |
+   |                                          referenced constant has errors
+   |
+   = 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 #71800 <https://github.com/rust-lang/rust/issues/71800>
+
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:103:1
+  --> $DIR/ub-wide-ptr.rs:109:1
    |
 LL | / const RAW_SLICE_LENGTH_UNINIT: *const [u8] = unsafe {
 LL | |
@@ -187,7 +220,7 @@ LL | | };
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:111:1
+  --> $DIR/ub-wide-ptr.rs:117:1
    |
 LL | const TRAIT_OBJ_SHORT_VTABLE_1: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u8))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered too small vtable
@@ -198,7 +231,7 @@ LL | const TRAIT_OBJ_SHORT_VTABLE_1: W<&dyn Trait> = unsafe { mem::transmute(W((
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:114:1
+  --> $DIR/ub-wide-ptr.rs:120:1
    |
 LL | const TRAIT_OBJ_SHORT_VTABLE_2: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u64))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered too small vtable
@@ -209,7 +242,7 @@ LL | const TRAIT_OBJ_SHORT_VTABLE_2: W<&dyn Trait> = unsafe { mem::transmute(W((
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:117:1
+  --> $DIR/ub-wide-ptr.rs:123:1
    |
 LL | const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, 4usize))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered dangling vtable pointer in wide pointer
@@ -220,7 +253,7 @@ LL | const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:119:1
+  --> $DIR/ub-wide-ptr.rs:125:1
    |
 LL | const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92u8, &[0u8; 128])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered unaligned vtable pointer in wide pointer
@@ -231,7 +264,7 @@ LL | const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:121:1
+  --> $DIR/ub-wide-ptr.rs:127:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92u8, &[0usize; 8])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -242,7 +275,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:123:1
+  --> $DIR/ub-wide-ptr.rs:129:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u8, &[1usize; 8])) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -253,7 +286,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:125:1
+  --> $DIR/ub-wide-ptr.rs:131:1
    |
 LL | const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &[&42u8; 8]))) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered invalid drop function pointer in vtable (not pointing to a function)
@@ -264,7 +297,7 @@ LL | const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::trans
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:129:1
+  --> $DIR/ub-wide-ptr.rs:135:1
    |
 LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, &bool>(&3u8) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.<dyn-downcast>: encountered 0x03, but expected a boolean
@@ -275,7 +308,7 @@ LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_,
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:133:1
+  --> $DIR/ub-wide-ptr.rs:139:1
    |
 LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling vtable pointer in wide pointer
@@ -286,7 +319,7 @@ LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute
            }
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-wide-ptr.rs:135:1
+  --> $DIR/ub-wide-ptr.rs:141:1
    |
 LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered too small vtable
@@ -297,17 +330,17 @@ LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transm
            }
 
 error[E0080]: could not evaluate static initializer
-  --> $DIR/ub-wide-ptr.rs:141:5
+  --> $DIR/ub-wide-ptr.rs:147:5
    |
 LL |     mem::transmute::<_, &dyn Trait>((&92u8, 0usize))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: null pointer is not a valid pointer
 
 error[E0080]: could not evaluate static initializer
-  --> $DIR/ub-wide-ptr.rs:145:5
+  --> $DIR/ub-wide-ptr.rs:151:5
    |
 LL |     mem::transmute::<_, &dyn Trait>((&92u8, &3u64))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: allocN has size N, so pointer to 24 bytes starting at offset N is out-of-bounds
 
-error: aborting due to 29 previous errors
+error: aborting due to 32 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.rs b/src/test/ui/consts/const-eval/ub-wide-ptr.rs
index 763e6ba2967..f2e5738f88c 100644
--- a/src/test/ui/consts/const-eval/ub-wide-ptr.rs
+++ b/src/test/ui/consts/const-eval/ub-wide-ptr.rs
@@ -86,15 +86,21 @@ const SLICE_LENGTH_PTR_BOX: Box<[u8]> = unsafe { mem::transmute((&42u8, &3)) };
 // bad data *inside* the slice
 const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
 //~^ ERROR it is undefined behavior to use this value
+//~| ERROR any use of this value will cause an error
+//~| WARNING this was previously accepted
 
 // good MySliceBool
 const MYSLICE_GOOD: &MySliceBool = &MySlice(true, [false]);
 // bad: sized field is not okay
 const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
 //~^ ERROR it is undefined behavior to use this value
+//~| ERROR any use of this value will cause an error
+//~| WARNING this was previously accepted
 // bad: unsized part is not okay
 const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
 //~^ ERROR it is undefined behavior to use this value
+//~| ERROR any use of this value will cause an error
+//~| WARNING this was previously accepted
 
 // # raw slice
 const RAW_SLICE_VALID: *const [u8] = unsafe { mem::transmute((&42u8, 1usize)) }; // ok