Auto merge of #115748 - RalfJung:post-mono, r=oli-obk

move required_consts check to general post-mono-check function

This factors some code that is common between the interpreter and the codegen backends into shared helper functions. Also as a side-effect the interpreter now uses the same `eval` functions as everyone else to get the evaluated MIR constants.

Also this is in preparation for another post-mono check that will be needed for (the current hackfix for) https://github.com/rust-lang/rust/issues/115709: ensuring that all locals are dynamically sized.

I didn't expect this to change diagnostics, but it's just cycle errors that change.

r? `@oli-obk`

38 files changed, 150 insertions, 75 deletions

diff --git a/tests/ui/associated-consts/defaults-cyclic-fail.rs b/tests/ui/associated-consts/defaults-cyclic-fail.rs
index a1c6840a0f1..9ef0003da17 100644
--- a/tests/ui/associated-consts/defaults-cyclic-fail.rs
+++ b/tests/ui/associated-consts/defaults-cyclic-fail.rs
@@ -3,7 +3,7 @@
 // Cyclic assoc. const defaults don't error unless *used*
 trait Tr {
     const A: u8 = Self::B;
-    //~^ cycle detected when const-evaluating + checking `Tr::A`
+    //~^ cycle detected
 
     const B: u8 = Self::A;
 }
diff --git a/tests/ui/associated-consts/defaults-cyclic-fail.stderr b/tests/ui/associated-consts/defaults-cyclic-fail.stderr
index ebdb76e4286..e29c32f5dfd 100644
--- a/tests/ui/associated-consts/defaults-cyclic-fail.stderr
+++ b/tests/ui/associated-consts/defaults-cyclic-fail.stderr
@@ -1,15 +1,25 @@
-error[E0391]: cycle detected when const-evaluating + checking `Tr::A`
+error[E0391]: cycle detected when simplifying constant for the type system `Tr::A`
+  --> $DIR/defaults-cyclic-fail.rs:5:5
+   |
+LL |     const A: u8 = Self::B;
+   |     ^^^^^^^^^^^
+   |
+note: ...which requires const-evaluating + checking `Tr::A`...
   --> $DIR/defaults-cyclic-fail.rs:5:19
    |
 LL |     const A: u8 = Self::B;
    |                   ^^^^^^^
+note: ...which requires simplifying constant for the type system `Tr::B`...
+  --> $DIR/defaults-cyclic-fail.rs:8:5
    |
+LL |     const B: u8 = Self::A;
+   |     ^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `Tr::B`...
   --> $DIR/defaults-cyclic-fail.rs:8:19
    |
 LL |     const B: u8 = Self::A;
    |                   ^^^^^^^
-   = note: ...which again requires const-evaluating + checking `Tr::A`, completing the cycle
+   = note: ...which again requires simplifying constant for the type system `Tr::A`, completing the cycle
 note: cycle used when const-evaluating + checking `main::promoted[1]`
   --> $DIR/defaults-cyclic-fail.rs:16:16
    |
diff --git a/tests/ui/associated-consts/defaults-not-assumed-fail.stderr b/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
index 9b761b00691..d659912341a 100644
--- a/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
+++ b/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
@@ -4,13 +4,13 @@ error[E0080]: evaluation of `<() as Tr>::B` failed
 LL |     const B: u8 = Self::A + 1;
    |                   ^^^^^^^^^^^ attempt to compute `u8::MAX + 1_u8`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/defaults-not-assumed-fail.rs:33:16
    |
 LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
    |                ^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/defaults-not-assumed-fail.rs:33:5
    |
 LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
@@ -18,7 +18,7 @@ LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
    |
    = note: this note originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/defaults-not-assumed-fail.rs:33:5
    |
 LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
index 51bf0cb5e5c..4418fb7556b 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
@@ -4,7 +4,12 @@ error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-249
 LL |     const BAR: u32 = IMPL_REF_BAR;
    |                      ^^^^^^^^^^^^
    |
-note: ...which requires const-evaluating + checking `IMPL_REF_BAR`...
+note: ...which requires simplifying constant for the type system `IMPL_REF_BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:7:1
+   |
+LL | const IMPL_REF_BAR: u32 = GlobalImplRef::BAR;
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `IMPL_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:7:1
    |
 LL | const IMPL_REF_BAR: u32 = GlobalImplRef::BAR;
@@ -14,6 +19,11 @@ note: ...which requires const-evaluating + checking `IMPL_REF_BAR`...
    |
 LL | const IMPL_REF_BAR: u32 = GlobalImplRef::BAR;
    |                           ^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:5
+   |
+LL |     const BAR: u32 = IMPL_REF_BAR;
+   |     ^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:5
    |
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
index 8277d41a1c9..392cd5e3443 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
@@ -4,7 +4,12 @@ error[E0391]: cycle detected when elaborating drops for `FooDefault::BAR`
 LL |     const BAR: u32 = DEFAULT_REF_BAR;
    |                      ^^^^^^^^^^^^^^^
    |
-note: ...which requires const-evaluating + checking `DEFAULT_REF_BAR`...
+note: ...which requires simplifying constant for the type system `DEFAULT_REF_BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:11:1
+   |
+LL | const DEFAULT_REF_BAR: u32 = <GlobalDefaultRef>::BAR;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `DEFAULT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:11:1
    |
 LL | const DEFAULT_REF_BAR: u32 = <GlobalDefaultRef>::BAR;
@@ -14,6 +19,11 @@ note: ...which requires const-evaluating + checking `DEFAULT_REF_BAR`...
    |
 LL | const DEFAULT_REF_BAR: u32 = <GlobalDefaultRef>::BAR;
    |                              ^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `FooDefault::BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:5
+   |
+LL |     const BAR: u32 = DEFAULT_REF_BAR;
+   |     ^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `FooDefault::BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:5
    |
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
index 9983ba794cd..6cbddca9c62 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
@@ -4,7 +4,12 @@ error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-249
 LL |     const BAR: u32 = TRAIT_REF_BAR;
    |                      ^^^^^^^^^^^^^
    |
-note: ...which requires const-evaluating + checking `TRAIT_REF_BAR`...
+note: ...which requires simplifying constant for the type system `TRAIT_REF_BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:7:1
+   |
+LL | const TRAIT_REF_BAR: u32 = <GlobalTraitRef>::BAR;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `TRAIT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:7:1
    |
 LL | const TRAIT_REF_BAR: u32 = <GlobalTraitRef>::BAR;
@@ -14,6 +19,11 @@ note: ...which requires const-evaluating + checking `TRAIT_REF_BAR`...
    |
 LL | const TRAIT_REF_BAR: u32 = <GlobalTraitRef>::BAR;
    |                            ^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires simplifying constant for the type system `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`...
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:5
+   |
+LL |     const BAR: u32 = TRAIT_REF_BAR;
+   |     ^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:5
    |
diff --git a/tests/ui/borrowck/issue-81899.stderr b/tests/ui/borrowck/issue-81899.stderr
index 1b03bc3af9c..63e817239c6 100644
--- a/tests/ui/borrowck/issue-81899.stderr
+++ b/tests/ui/borrowck/issue-81899.stderr
@@ -16,7 +16,7 @@ LL | const _CONST: &[u8] = &f(&[], |_| {});
    |                        ^^^^^^^^^^^^^^
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-81899.rs:4:23
    |
 LL | const _CONST: &[u8] = &f(&[], |_| {});
diff --git a/tests/ui/borrowck/issue-88434-minimal-example.stderr b/tests/ui/borrowck/issue-88434-minimal-example.stderr
index a5a571c6d4d..4c887b2ad42 100644
--- a/tests/ui/borrowck/issue-88434-minimal-example.stderr
+++ b/tests/ui/borrowck/issue-88434-minimal-example.stderr
@@ -16,7 +16,7 @@ LL | const _CONST: &() = &f(&|_| {});
    |                      ^^^^^^^^^^
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-88434-minimal-example.rs:3:21
    |
 LL | const _CONST: &() = &f(&|_| {});
diff --git a/tests/ui/borrowck/issue-88434-removal-index-should-be-less.stderr b/tests/ui/borrowck/issue-88434-removal-index-should-be-less.stderr
index 00023c459a8..f7257817a8b 100644
--- a/tests/ui/borrowck/issue-88434-removal-index-should-be-less.stderr
+++ b/tests/ui/borrowck/issue-88434-removal-index-should-be-less.stderr
@@ -16,7 +16,7 @@ LL | const _CONST: &[u8] = &f(&[], |_| {});
    |                        ^^^^^^^^^^^^^^
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-88434-removal-index-should-be-less.rs:3:23
    |
 LL | const _CONST: &[u8] = &f(&[], |_| {});
diff --git a/tests/ui/consts/const-err-late.stderr b/tests/ui/consts/const-err-late.stderr
index 149d3b5236b..85bc56baed8 100644
--- a/tests/ui/consts/const-err-late.stderr
+++ b/tests/ui/consts/const-err-late.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `S::<i32>::FOO` failed
 LL |     const FOO: u8 = [5u8][1];
    |                     ^^^^^^^^ index out of bounds: the length is 1 but the index is 1
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-late.rs:19:16
    |
 LL |     black_box((S::<i32>::FOO, S::<u32>::FOO));
@@ -16,13 +16,13 @@ error[E0080]: evaluation of `S::<u32>::FOO` failed
 LL |     const FOO: u8 = [5u8][1];
    |                     ^^^^^^^^ index out of bounds: the length is 1 but the index is 1
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-late.rs:19:31
    |
 LL |     black_box((S::<i32>::FOO, S::<u32>::FOO));
    |                               ^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-late.rs:19:16
    |
 LL |     black_box((S::<i32>::FOO, S::<u32>::FOO));
diff --git a/tests/ui/consts/const-err-multi.stderr b/tests/ui/consts/const-err-multi.stderr
index 28af8e5eb09..1ad504b3a80 100644
--- a/tests/ui/consts/const-err-multi.stderr
+++ b/tests/ui/consts/const-err-multi.stderr
@@ -4,19 +4,19 @@ error[E0080]: evaluation of constant value failed
 LL | pub const A: i8 = -i8::MIN;
    |                   ^^^^^^^^ attempt to negate `i8::MIN`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-multi.rs:3:19
    |
 LL | pub const B: i8 = A;
    |                   ^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-multi.rs:5:19
    |
 LL | pub const C: u8 = A as u8;
    |                   ^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-err-multi.rs:7:24
    |
 LL | pub const D: i8 = 50 - A;
diff --git a/tests/ui/consts/const-eval/erroneous-const.stderr b/tests/ui/consts/const-eval/erroneous-const.stderr
index 770f95062ab..0e31520fdbb 100644
--- a/tests/ui/consts/const-eval/erroneous-const.stderr
+++ b/tests/ui/consts/const-eval/erroneous-const.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `PrintName::<i32>::VOID` failed
 LL |     const VOID: () = [()][2];
    |                      ^^^^^^^ index out of bounds: the length is 1 but the index is 2
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/erroneous-const.rs:13:13
    |
 LL |             PrintName::<T>::VOID;
diff --git a/tests/ui/consts/const-eval/erroneous-const2.stderr b/tests/ui/consts/const-eval/erroneous-const2.stderr
index 082c2876575..4ca44694cd7 100644
--- a/tests/ui/consts/const-eval/erroneous-const2.stderr
+++ b/tests/ui/consts/const-eval/erroneous-const2.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `PrintName::<i32>::VOID` failed
 LL |     const VOID: () = [()][2];
    |                      ^^^^^^^ index out of bounds: the length is 1 but the index is 2
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/erroneous-const2.rs:13:9
    |
 LL |         PrintName::<i32>::VOID;
diff --git a/tests/ui/consts/const-eval/issue-44578.stderr b/tests/ui/consts/const-eval/issue-44578.stderr
index f3952809e4b..c7aaee94271 100644
--- a/tests/ui/consts/const-eval/issue-44578.stderr
+++ b/tests/ui/consts/const-eval/issue-44578.stderr
@@ -4,13 +4,13 @@ error[E0080]: evaluation of `<Bar<u16, u8> as Foo>::AMT` failed
 LL |     const AMT: usize = [A::AMT][(A::AMT > B::AMT) as usize];
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ index out of bounds: the length is 1 but the index is 1
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-44578.rs:25:20
    |
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-44578.rs:25:20
    |
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
@@ -18,7 +18,7 @@ LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
    |
    = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-44578.rs:25:20
    |
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
diff --git a/tests/ui/consts/const-eval/issue-50814-2.stderr b/tests/ui/consts/const-eval/issue-50814-2.stderr
index 956f7aec9da..450fb002373 100644
--- a/tests/ui/consts/const-eval/issue-50814-2.stderr
+++ b/tests/ui/consts/const-eval/issue-50814-2.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `<A<()> as Foo<()>>::BAR` failed
 LL |     const BAR: usize = [5, 6, 7][T::BOO];
    |                        ^^^^^^^^^^^^^^^^^ index out of bounds: the length is 3 but the index is 42
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-50814-2.rs:18:6
    |
 LL |     &<A<T> as Foo<T>>::BAR
diff --git a/tests/ui/consts/const-eval/issue-50814.stderr b/tests/ui/consts/const-eval/issue-50814.stderr
index 05b6271f4e4..48a20d0bbd0 100644
--- a/tests/ui/consts/const-eval/issue-50814.stderr
+++ b/tests/ui/consts/const-eval/issue-50814.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `<Sum<U8, U8> as Unsigned>::MAX` failed
 LL |     const MAX: u8 = A::MAX + B::MAX;
    |                     ^^^^^^^^^^^^^^^ attempt to compute `u8::MAX + u8::MAX`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-50814.rs:20:6
    |
 LL |     &Sum::<U8, U8>::MAX
diff --git a/tests/ui/consts/const-eval/panic-assoc-never-type.rs b/tests/ui/consts/const-eval/panic-assoc-never-type.rs
index 1abe708d19e..88ce5b0d895 100644
--- a/tests/ui/consts/const-eval/panic-assoc-never-type.rs
+++ b/tests/ui/consts/const-eval/panic-assoc-never-type.rs
@@ -11,5 +11,5 @@ impl PrintName {
 }
 
 fn main() {
-    let _ = PrintName::VOID; //~ erroneous constant used
+    let _ = PrintName::VOID; //~ erroneous constant encountered
 }
diff --git a/tests/ui/consts/const-eval/panic-assoc-never-type.stderr b/tests/ui/consts/const-eval/panic-assoc-never-type.stderr
index 7c36a3a426e..4706497dbc4 100644
--- a/tests/ui/consts/const-eval/panic-assoc-never-type.stderr
+++ b/tests/ui/consts/const-eval/panic-assoc-never-type.stderr
@@ -6,13 +6,13 @@ LL |     const VOID: ! = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/panic-assoc-never-type.rs:14:13
    |
 LL |     let _ = PrintName::VOID;
    |             ^^^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/panic-assoc-never-type.rs:14:13
    |
 LL |     let _ = PrintName::VOID;
diff --git a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
index e087a0ebec7..042e7eeb31e 100644
--- a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
+++ b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
@@ -341,7 +341,7 @@ LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
                ╾ALLOC_ID╼                                     │ ╾──╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:160:40
    |
 LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
@@ -358,7 +358,7 @@ LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3
                ╾ALLOC_ID╼                                     │ ╾──╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:166:42
    |
 LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
@@ -375,7 +375,7 @@ LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::tran
                ╾ALLOC_ID╼                                     │ ╾──╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:170:42
    |
 LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
diff --git a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
index 4c655161f79..8426a95055c 100644
--- a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
+++ b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
@@ -341,7 +341,7 @@ LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
                ╾ALLOC_ID╼                         │ ╾──────╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:160:40
    |
 LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
@@ -358,7 +358,7 @@ LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3
                ╾ALLOC_ID╼                         │ ╾──────╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:166:42
    |
 LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
@@ -375,7 +375,7 @@ LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::tran
                ╾ALLOC_ID╼                         │ ╾──────╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/raw-bytes.rs:170:42
    |
 LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
diff --git a/tests/ui/consts/const-eval/ub-ref-ptr.stderr b/tests/ui/consts/const-eval/ub-ref-ptr.stderr
index 0ee1e60877f..6d5c36cea7d 100644
--- a/tests/ui/consts/const-eval/ub-ref-ptr.stderr
+++ b/tests/ui/consts/const-eval/ub-ref-ptr.stderr
@@ -60,7 +60,7 @@ LL | const REF_AS_USIZE_SLICE: &[usize] = &[unsafe { mem::transmute(&0) }];
    = help: this code performed an operation that depends on the underlying bytes representing a pointer
    = help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/ub-ref-ptr.rs:36:38
    |
 LL | const REF_AS_USIZE_SLICE: &[usize] = &[unsafe { mem::transmute(&0) }];
@@ -75,7 +75,7 @@ LL | const REF_AS_USIZE_BOX_SLICE: Box<[usize]> = unsafe { mem::transmute::<&[us
    = help: this code performed an operation that depends on the underlying bytes representing a pointer
    = help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/ub-ref-ptr.rs:39:85
    |
 LL | const REF_AS_USIZE_BOX_SLICE: Box<[usize]> = unsafe { mem::transmute::<&[usize], _>(&[mem::transmute(&0)]) };
diff --git a/tests/ui/consts/const-eval/ub-wide-ptr.stderr b/tests/ui/consts/const-eval/ub-wide-ptr.stderr
index 02bbbf50435..d8add67fac1 100644
--- a/tests/ui/consts/const-eval/ub-wide-ptr.stderr
+++ b/tests/ui/consts/const-eval/ub-wide-ptr.stderr
@@ -139,7 +139,7 @@ LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
                HEX_DUMP
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/ub-wide-ptr.rs:85:40
    |
 LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
@@ -156,7 +156,7 @@ LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3
                HEX_DUMP
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/ub-wide-ptr.rs:92:42
    |
 LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
@@ -173,7 +173,7 @@ LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::tran
                HEX_DUMP
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/ub-wide-ptr.rs:96:42
    |
 LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
diff --git a/tests/ui/consts/const-eval/union-const-eval-field.stderr b/tests/ui/consts/const-eval/union-const-eval-field.stderr
index 9899c56c0ec..ce260300fc8 100644
--- a/tests/ui/consts/const-eval/union-const-eval-field.stderr
+++ b/tests/ui/consts/const-eval/union-const-eval-field.stderr
@@ -4,13 +4,13 @@ error[E0080]: evaluation of constant value failed
 LL |     const FIELD3: Field3 = unsafe { UNION.field3 };
    |                                     ^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/union-const-eval-field.rs:31:5
    |
 LL |     FIELD3
    |     ^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/union-const-eval-field.rs:31:5
    |
 LL |     FIELD3
diff --git a/tests/ui/consts/const-float-bits-reject-conv.stderr b/tests/ui/consts/const-float-bits-reject-conv.stderr
index 7ad02252094..1511dab12b0 100644
--- a/tests/ui/consts/const-float-bits-reject-conv.stderr
+++ b/tests/ui/consts/const-float-bits-reject-conv.stderr
@@ -30,25 +30,25 @@ LL |     const MASKED_NAN2: u32 = f32::NAN.to_bits() ^ 0x0055_5555;
    |                              ^^^^^^^^^^^^^^^^^^
    = note: this error originates in the macro `$crate::panic::panic_2021` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:35:34
    |
 LL |     const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:36:34
    |
 LL |     const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:42:34
    |
 LL |     const_assert!(f32::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:43:34
    |
 LL |     const_assert!(f32::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
@@ -86,25 +86,25 @@ LL |     const MASKED_NAN2: u64 = f64::NAN.to_bits() ^ 0x0005_5555_5555_5555;
    |                              ^^^^^^^^^^^^^^^^^^
    = note: this error originates in the macro `$crate::panic::panic_2021` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:57:34
    |
 LL |     const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:58:34
    |
 LL |     const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:61:34
    |
 LL |     const_assert!(f64::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
    |                                  ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-float-bits-reject-conv.rs:62:34
    |
 LL |     const_assert!(f64::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
diff --git a/tests/ui/consts/const-len-underflow-separate-spans.next.stderr b/tests/ui/consts/const-len-underflow-separate-spans.next.stderr
index d9208d0706a..b7b5b648c12 100644
--- a/tests/ui/consts/const-len-underflow-separate-spans.next.stderr
+++ b/tests/ui/consts/const-len-underflow-separate-spans.next.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 LL | const LEN: usize = ONE - TWO;
    |                    ^^^^^^^^^ attempt to compute `1_usize - 2_usize`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-len-underflow-separate-spans.rs:14:17
    |
 LL |     let a: [i8; LEN] = unimplemented!();
diff --git a/tests/ui/consts/const-len-underflow-separate-spans.old.stderr b/tests/ui/consts/const-len-underflow-separate-spans.old.stderr
index d9208d0706a..b7b5b648c12 100644
--- a/tests/ui/consts/const-len-underflow-separate-spans.old.stderr
+++ b/tests/ui/consts/const-len-underflow-separate-spans.old.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 LL | const LEN: usize = ONE - TWO;
    |                    ^^^^^^^^^ attempt to compute `1_usize - 2_usize`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-len-underflow-separate-spans.rs:14:17
    |
 LL |     let a: [i8; LEN] = unimplemented!();
diff --git a/tests/ui/consts/invalid-union.32bit.stderr b/tests/ui/consts/invalid-union.32bit.stderr
index 0dd18a55786..b6cf060e5ae 100644
--- a/tests/ui/consts/invalid-union.32bit.stderr
+++ b/tests/ui/consts/invalid-union.32bit.stderr
@@ -9,13 +9,13 @@ LL | fn main() {
                ╾─alloc7──╼                                     │ ╾──╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/invalid-union.rs:43:25
    |
 LL |     let _: &'static _ = &C;
    |                         ^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/invalid-union.rs:43:25
    |
 LL |     let _: &'static _ = &C;
diff --git a/tests/ui/consts/invalid-union.64bit.stderr b/tests/ui/consts/invalid-union.64bit.stderr
index 07f36ee2832..e3a3ef62c4a 100644
--- a/tests/ui/consts/invalid-union.64bit.stderr
+++ b/tests/ui/consts/invalid-union.64bit.stderr
@@ -9,13 +9,13 @@ LL | fn main() {
                ╾───────alloc7────────╼                         │ ╾──────╼
            }
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/invalid-union.rs:43:25
    |
 LL |     let _: &'static _ = &C;
    |                         ^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/invalid-union.rs:43:25
    |
 LL |     let _: &'static _ = &C;
diff --git a/tests/ui/consts/issue-36163.stderr b/tests/ui/consts/issue-36163.stderr
index 190b41062f8..6fcfe3ed28c 100644
--- a/tests/ui/consts/issue-36163.stderr
+++ b/tests/ui/consts/issue-36163.stderr
@@ -1,15 +1,25 @@
-error[E0391]: cycle detected when const-evaluating + checking `Foo::B::{constant#0}`
+error[E0391]: cycle detected when simplifying constant for the type system `Foo::B::{constant#0}`
   --> $DIR/issue-36163.rs:4:9
    |
 LL |     B = A,
    |         ^
    |
+note: ...which requires const-evaluating + checking `Foo::B::{constant#0}`...
+  --> $DIR/issue-36163.rs:4:9
+   |
+LL |     B = A,
+   |         ^
+note: ...which requires simplifying constant for the type system `A`...
+  --> $DIR/issue-36163.rs:1:1
+   |
+LL | const A: isize = Foo::B as isize;
+   | ^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `A`...
   --> $DIR/issue-36163.rs:1:18
    |
 LL | const A: isize = Foo::B as isize;
    |                  ^^^^^^^^^^^^^^^
-   = note: ...which again requires const-evaluating + checking `Foo::B::{constant#0}`, completing the cycle
+   = note: ...which again requires simplifying constant for the type system `Foo::B::{constant#0}`, completing the cycle
 note: cycle used when simplifying constant for the type system `Foo::B::{constant#0}`
   --> $DIR/issue-36163.rs:4:9
    |
diff --git a/tests/ui/consts/miri_unleashed/assoc_const.stderr b/tests/ui/consts/miri_unleashed/assoc_const.stderr
index d97097d352a..274b1de7e7d 100644
--- a/tests/ui/consts/miri_unleashed/assoc_const.stderr
+++ b/tests/ui/consts/miri_unleashed/assoc_const.stderr
@@ -13,13 +13,13 @@ note: inside `<String as Bar<Vec<u32>, String>>::F`
 LL |     const F: u32 = (U::X, 42).1;
    |                               ^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/assoc_const.rs:29:13
    |
 LL |     let y = <String as Bar<Vec<u32>, String>>::F;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/assoc_const.rs:29:13
    |
 LL |     let y = <String as Bar<Vec<u32>, String>>::F;
diff --git a/tests/ui/consts/miri_unleashed/assoc_const_2.stderr b/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
index ae7b03fc9dd..c8e4cab4e71 100644
--- a/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
+++ b/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
@@ -4,13 +4,13 @@ error[E0080]: evaluation of `<std::string::String as Bar<std::string::String>>::
 LL |     const F: u32 = 100 / U::X;
    |                    ^^^^^^^^^^ attempt to divide `100_u32` by zero
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/assoc_const_2.rs:27:13
    |
 LL |     let y = <String as Bar<String>>::F;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/assoc_const_2.rs:27:13
    |
 LL |     let y = <String as Bar<String>>::F;
diff --git a/tests/ui/consts/uninhabited-const-issue-61744.stderr b/tests/ui/consts/uninhabited-const-issue-61744.stderr
index adefbf336c2..f48e6c4ce51 100644
--- a/tests/ui/consts/uninhabited-const-issue-61744.stderr
+++ b/tests/ui/consts/uninhabited-const-issue-61744.stderr
@@ -645,13 +645,13 @@ note: inside `<i32 as Const>::CONSTANT`
 LL |     const CONSTANT: i32 = unsafe { fake_type() };
    |                                    ^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/uninhabited-const-issue-61744.rs:18:10
    |
 LL |     dbg!(i32::CONSTANT);
    |          ^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/uninhabited-const-issue-61744.rs:18:10
    |
 LL |     dbg!(i32::CONSTANT);
diff --git a/tests/ui/issues/issue-17252.stderr b/tests/ui/issues/issue-17252.stderr
index daaf82e80ad..32e20d77465 100644
--- a/tests/ui/issues/issue-17252.stderr
+++ b/tests/ui/issues/issue-17252.stderr
@@ -1,10 +1,15 @@
-error[E0391]: cycle detected when const-evaluating + checking `FOO`
+error[E0391]: cycle detected when simplifying constant for the type system `FOO`
+  --> $DIR/issue-17252.rs:1:1
+   |
+LL | const FOO: usize = FOO;
+   | ^^^^^^^^^^^^^^^^
+   |
+note: ...which requires const-evaluating + checking `FOO`...
   --> $DIR/issue-17252.rs:1:20
    |
 LL | const FOO: usize = FOO;
    |                    ^^^
-   |
-   = note: ...which immediately requires const-evaluating + checking `FOO` again
+   = note: ...which again requires simplifying constant for the type system `FOO`, completing the cycle
 note: cycle used when const-evaluating + checking `main::{constant#0}`
   --> $DIR/issue-17252.rs:4:18
    |
diff --git a/tests/ui/issues/issue-23302-1.stderr b/tests/ui/issues/issue-23302-1.stderr
index d807e24403e..d753bdeb9f7 100644
--- a/tests/ui/issues/issue-23302-1.stderr
+++ b/tests/ui/issues/issue-23302-1.stderr
@@ -1,10 +1,15 @@
-error[E0391]: cycle detected when const-evaluating + checking `X::A::{constant#0}`
+error[E0391]: cycle detected when simplifying constant for the type system `X::A::{constant#0}`
   --> $DIR/issue-23302-1.rs:4:9
    |
 LL |     A = X::A as isize,
    |         ^^^^^^^^^^^^^
    |
-   = note: ...which immediately requires const-evaluating + checking `X::A::{constant#0}` again
+note: ...which requires const-evaluating + checking `X::A::{constant#0}`...
+  --> $DIR/issue-23302-1.rs:4:9
+   |
+LL |     A = X::A as isize,
+   |         ^^^^^^^^^^^^^
+   = note: ...which again requires simplifying constant for the type system `X::A::{constant#0}`, completing the cycle
 note: cycle used when simplifying constant for the type system `X::A::{constant#0}`
   --> $DIR/issue-23302-1.rs:4:9
    |
diff --git a/tests/ui/issues/issue-23302-2.stderr b/tests/ui/issues/issue-23302-2.stderr
index 91b39dba1ba..b756ee1d5e2 100644
--- a/tests/ui/issues/issue-23302-2.stderr
+++ b/tests/ui/issues/issue-23302-2.stderr
@@ -1,10 +1,15 @@
-error[E0391]: cycle detected when const-evaluating + checking `Y::A::{constant#0}`
+error[E0391]: cycle detected when simplifying constant for the type system `Y::A::{constant#0}`
   --> $DIR/issue-23302-2.rs:4:9
    |
 LL |     A = Y::B as isize,
    |         ^^^^^^^^^^^^^
    |
-   = note: ...which immediately requires const-evaluating + checking `Y::A::{constant#0}` again
+note: ...which requires const-evaluating + checking `Y::A::{constant#0}`...
+  --> $DIR/issue-23302-2.rs:4:9
+   |
+LL |     A = Y::B as isize,
+   |         ^^^^^^^^^^^^^
+   = note: ...which again requires simplifying constant for the type system `Y::A::{constant#0}`, completing the cycle
 note: cycle used when simplifying constant for the type system `Y::A::{constant#0}`
   --> $DIR/issue-23302-2.rs:4:9
    |
diff --git a/tests/ui/issues/issue-23302-3.stderr b/tests/ui/issues/issue-23302-3.stderr
index 6b708d81f73..6cdc94551fe 100644
--- a/tests/ui/issues/issue-23302-3.stderr
+++ b/tests/ui/issues/issue-23302-3.stderr
@@ -1,15 +1,25 @@
-error[E0391]: cycle detected when const-evaluating + checking `A`
+error[E0391]: cycle detected when simplifying constant for the type system `A`
+  --> $DIR/issue-23302-3.rs:1:1
+   |
+LL | const A: i32 = B;
+   | ^^^^^^^^^^^^
+   |
+note: ...which requires const-evaluating + checking `A`...
   --> $DIR/issue-23302-3.rs:1:16
    |
 LL | const A: i32 = B;
    |                ^
+note: ...which requires simplifying constant for the type system `B`...
+  --> $DIR/issue-23302-3.rs:3:1
    |
+LL | const B: i32 = A;
+   | ^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `B`...
   --> $DIR/issue-23302-3.rs:3:16
    |
 LL | const B: i32 = A;
    |                ^
-   = note: ...which again requires const-evaluating + checking `A`, completing the cycle
+   = note: ...which again requires simplifying constant for the type system `A`, completing the cycle
 note: cycle used when simplifying constant for the type system `A`
   --> $DIR/issue-23302-3.rs:1:1
    |
diff --git a/tests/ui/issues/issue-69602-type-err-during-codegen-ice.stderr b/tests/ui/issues/issue-69602-type-err-during-codegen-ice.stderr
index ba385d887fb..6f9302bc4a5 100644
--- a/tests/ui/issues/issue-69602-type-err-during-codegen-ice.stderr
+++ b/tests/ui/issues/issue-69602-type-err-during-codegen-ice.stderr
@@ -13,7 +13,7 @@ LL |     type MyA: TraitA;
 LL | impl TraitB for B {
    | ^^^^^^^^^^^^^^^^^ missing `MyA` in implementation
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-69602-type-err-during-codegen-ice.rs:21:17
    |
 LL |     let _ = [0; B::VALUE];
diff --git a/tests/ui/limits/issue-55878.stderr b/tests/ui/limits/issue-55878.stderr
index f0c7210dde7..93716c0b347 100644
--- a/tests/ui/limits/issue-55878.stderr
+++ b/tests/ui/limits/issue-55878.stderr
@@ -11,7 +11,7 @@ note: inside `main`
 LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-55878.rs:7:26
    |
 LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());
@@ -19,7 +19,7 @@ LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());
    |
    = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/issue-55878.rs:7:26
    |
 LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());