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`

7 files changed, 10 insertions, 11 deletions

diff --git a/src/tools/clippy/clippy_lints/src/non_copy_const.rs b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
index 243192385c2..88466333787 100644
--- a/src/tools/clippy/clippy_lints/src/non_copy_const.rs
+++ b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
@@ -204,7 +204,7 @@ fn is_value_unfrozen_raw<'tcx>(
             // similar to 2., but with the a frozen variant) (e.g. borrowing
             // `borrow_interior_mutable_const::enums::AssocConsts::TO_BE_FROZEN_VARIANT`).
             // I chose this way because unfrozen enums as assoc consts are rare (or, hopefully, none).
-            err == ErrorHandled::TooGeneric
+            matches!(err, ErrorHandled::TooGeneric(..))
         },
         |val| val.map_or(true, |val| inner(cx, val, ty)),
     )
@@ -244,8 +244,8 @@ pub fn const_eval_resolve<'tcx>(
             };
             tcx.const_eval_global_id_for_typeck(param_env, cid, span)
         },
-        Ok(None) => Err(ErrorHandled::TooGeneric),
-        Err(err) => Err(ErrorHandled::Reported(err.into())),
+        Ok(None) => Err(ErrorHandled::TooGeneric(span.unwrap_or(rustc_span::DUMMY_SP))),
+        Err(err) => Err(ErrorHandled::Reported(err.into(), span.unwrap_or(rustc_span::DUMMY_SP))),
     }
 }
 
diff --git a/src/tools/clippy/tests/ui-toml/suppress_lint_in_const/test.stderr b/src/tools/clippy/tests/ui-toml/suppress_lint_in_const/test.stderr
index d14974faffa..f8ace799593 100644
--- a/src/tools/clippy/tests/ui-toml/suppress_lint_in_const/test.stderr
+++ b/src/tools/clippy/tests/ui-toml/suppress_lint_in_const/test.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of `main::{constant#3}` failed
 LL |     const { &ARR[idx4()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
    |              ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/test.rs:37:5
    |
 LL |     const { &ARR[idx4()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
diff --git a/src/tools/clippy/tests/ui/indexing_slicing_index.stderr b/src/tools/clippy/tests/ui/indexing_slicing_index.stderr
index 64facf20803..1c34875d2b8 100644
--- a/src/tools/clippy/tests/ui/indexing_slicing_index.stderr
+++ b/src/tools/clippy/tests/ui/indexing_slicing_index.stderr
@@ -24,7 +24,7 @@ error[E0080]: evaluation of `main::{constant#3}` failed
 LL |     const { &ARR[idx4()] };
    |              ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/indexing_slicing_index.rs:48:5
    |
 LL |     const { &ARR[idx4()] };
diff --git a/src/tools/miri/src/helpers.rs b/src/tools/miri/src/helpers.rs
index 0c7e8278147..72d9dbd045d 100644
--- a/src/tools/miri/src/helpers.rs
+++ b/src/tools/miri/src/helpers.rs
@@ -142,9 +142,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn eval_path_scalar(&self, path: &[&str]) -> Scalar<Provenance> {
         let this = self.eval_context_ref();
         let instance = this.resolve_path(path, Namespace::ValueNS);
-        let cid = GlobalId { instance, promoted: None };
         // We don't give a span -- this isn't actually used directly by the program anyway.
-        let const_val = this.eval_global(cid, None).unwrap_or_else(|err| {
+        let const_val = this.eval_global(instance).unwrap_or_else(|err| {
             panic!("failed to evaluate required Rust item: {path:?}\n{err:?}")
         });
         this.read_scalar(&const_val)
diff --git a/src/tools/miri/tests/fail/const-ub-checks.stderr b/src/tools/miri/tests/fail/const-ub-checks.stderr
index 596a6bb4ca8..d2b9018cd4b 100644
--- a/src/tools/miri/tests/fail/const-ub-checks.stderr
+++ b/src/tools/miri/tests/fail/const-ub-checks.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 LL |     ptr.read();
    |     ^^^^^^^^^^ accessing memory with alignment ALIGN, but alignment ALIGN is required
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/const-ub-checks.rs:LL:CC
    |
 LL |     let _x = UNALIGNED_READ;
diff --git a/src/tools/miri/tests/fail/erroneous_const.stderr b/src/tools/miri/tests/fail/erroneous_const.stderr
index 209c4a932dc..cacf866393d 100644
--- a/src/tools/miri/tests/fail/erroneous_const.stderr
+++ b/src/tools/miri/tests/fail/erroneous_const.stderr
@@ -6,7 +6,7 @@ LL |     const VOID: ! = panic!();
    |
    = note: this error originates in the macro `$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/erroneous_const.rs:LL:CC
    |
 LL |         let _ = PrintName::<T>::VOID;
diff --git a/src/tools/miri/tests/fail/erroneous_const2.stderr b/src/tools/miri/tests/fail/erroneous_const2.stderr
index 9aad1fc9b02..36e83b8f3bc 100644
--- a/src/tools/miri/tests/fail/erroneous_const2.stderr
+++ b/src/tools/miri/tests/fail/erroneous_const2.stderr
@@ -4,13 +4,13 @@ error[E0080]: evaluation of constant value failed
 LL | const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
    |                   ^^^^^ attempt to compute `5_u32 - 6_u32`, which would overflow
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/erroneous_const2.rs:LL:CC
    |
 LL |     println!("{}", FOO);
    |                    ^^^
 
-note: erroneous constant used
+note: erroneous constant encountered
   --> $DIR/erroneous_const2.rs:LL:CC
    |
 LL |     println!("{}", FOO);