Auto merge of #120980 - matthiaskrgr:rollup-dsjsqql, r=matthiaskrgr

Rollup of 11 pull requests

Successful merges:

 - #120765 (Reorder diagnostics API)
 - #120833 (More internal emit diagnostics cleanups)
 - #120899 (Gracefully handle non-WF alias in `assemble_alias_bound_candidates_recur`)
 - #120917 (Remove a bunch of dead parameters in functions)
 - #120928 (Add test for recently fixed issue)
 - #120933 (check_consts: fix duplicate errors, make importance consistent)
 - #120936 (improve `btree_cursors` functions documentation)
 - #120944 (Check that the ABI of the instance we are inlining is correct)
 - #120956 (Clean inlined type alias with correct param-env)
 - #120962 (Add myself to library/std review)
 - #120972 (fix ICE for deref coercions with type errors)

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -3018,7 +3018,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     /// assignment to `x.f`).
     pub(crate) fn report_illegal_reassignment(
         &mut self,
-        _location: Location,
         (place, span): (Place<'tcx>, Span),
         assigned_span: Span,
         err_place: Place<'tcx>,

compiler/rustc_borrowck/src/lib.rs

@@ -1036,7 +1036,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             self,
             self.infcx.tcx,
             self.body,
-            location,
             (sd, place_span.0),
             &borrow_set,
             |borrow_index| borrows_in_scope.contains(borrow_index),
@@ -2174,7 +2173,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 // report the error as an illegal reassignment
                 let init = &self.move_data.inits[init_index];
                 let assigned_span = init.span(self.body);
-                self.report_illegal_reassignment(location, (place, span), assigned_span, place);
+                self.report_illegal_reassignment((place, span), assigned_span, place);
             } else {
                 self.report_mutability_error(place, span, the_place_err, error_access, location)
             }

compiler/rustc_borrowck/src/path_utils.rs

@@ -27,7 +27,6 @@ pub(super) fn each_borrow_involving_path<'tcx, F, I, S>(
     s: &mut S,
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
-    _location: Location,
     access_place: (AccessDepth, Place<'tcx>),
     borrow_set: &BorrowSet<'tcx>,
     is_candidate: I,

compiler/rustc_borrowck/src/polonius/loan_invalidations.rs

@@ -340,7 +340,6 @@ impl<'cx, 'tcx> LoanInvalidationsGenerator<'cx, 'tcx> {
             self,
             self.tcx,
             self.body,
-            location,
             (sd, place),
             self.borrow_set,
             |_| true,

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -662,7 +662,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         polonius_output: Option<Rc<PoloniusOutput>>,
     ) -> (Option<ClosureRegionRequirements<'tcx>>, RegionErrors<'tcx>) {
         let mir_def_id = body.source.def_id();
-        self.propagate_constraints(body);
+        self.propagate_constraints();
 
         let mut errors_buffer = RegionErrors::new(infcx.tcx);
 
@@ -716,8 +716,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// for each region variable until all the constraints are
     /// satisfied. Note that some values may grow **too** large to be
     /// feasible, but we check this later.
-    #[instrument(skip(self, _body), level = "debug")]
+    #[instrument(skip(self), level = "debug")]
-    fn propagate_constraints(&mut self, _body: &Body<'tcx>) {
+    fn propagate_constraints(&mut self) {
         debug!("constraints={:#?}", {
             let mut constraints: Vec<_> = self.outlives_constraints().collect();
             constraints.sort_by_key(|c| (c.sup, c.sub));

compiler/rustc_const_eval/src/const_eval/error.rs

@@ -151,7 +151,7 @@ where
             let mut err = tcx.dcx().create_err(err);
 
             let msg = error.diagnostic_message();
-            error.add_args(tcx.dcx(), &mut err);
+            error.add_args(&mut err);
 
             // Use *our* span to label the interp error
             err.span_label(our_span, msg);

compiler/rustc_const_eval/src/errors.rs

@@ -426,7 +426,7 @@ pub struct UndefinedBehavior {
 pub trait ReportErrorExt {
     /// Returns the diagnostic message for this error.
     fn diagnostic_message(&self) -> DiagnosticMessage;
-    fn add_args<G: EmissionGuarantee>(self, dcx: &DiagCtxt, builder: &mut DiagnosticBuilder<'_, G>);
+    fn add_args<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>);
 
     fn debug(self) -> String
     where
@@ -434,11 +434,11 @@ pub trait ReportErrorExt {
     {
         ty::tls::with(move |tcx| {
             let dcx = tcx.dcx();
-            let mut builder = dcx.struct_allow(DiagnosticMessage::Str(String::new().into()));
+            let mut diag = dcx.struct_allow(DiagnosticMessage::Str(String::new().into()));
             let message = self.diagnostic_message();
-            self.add_args(dcx, &mut builder);
+            self.add_args(&mut diag);
-            let s = dcx.eagerly_translate_to_string(message, builder.args());
+            let s = dcx.eagerly_translate_to_string(message, diag.args());
-            builder.cancel();
+            diag.cancel();
             s
         })
     }
@@ -505,20 +505,17 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
         }
     }
 
-    fn add_args<G: EmissionGuarantee>(
+    fn add_args<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>) {
-        self,
-        dcx: &DiagCtxt,
-        builder: &mut DiagnosticBuilder<'_, G>,
-    ) {
         use UndefinedBehaviorInfo::*;
+        let dcx = diag.dcx;
         match self {
             Ub(_) => {}
             Custom(custom) => {
                 (custom.add_args)(&mut |name, value| {
-                    builder.arg(name, value);
+                    diag.arg(name, value);
                 });
             }
-            ValidationError(e) => e.add_args(dcx, builder),
+            ValidationError(e) => e.add_args(diag),
 
             Unreachable
             | DivisionByZero
@@ -533,20 +530,18 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
             | UninhabitedEnumVariantWritten(_)
             | UninhabitedEnumVariantRead(_) => {}
             BoundsCheckFailed { len, index } => {
-                builder.arg("len", len);
+                diag.arg("len", len);
-                builder.arg("index", index);
+                diag.arg("index", index);
             }
             UnterminatedCString(ptr) | InvalidFunctionPointer(ptr) | InvalidVTablePointer(ptr) => {
-                builder.arg("pointer", ptr);
+                diag.arg("pointer", ptr);
             }
             PointerUseAfterFree(alloc_id, msg) => {
-                builder
+                diag.arg("alloc_id", alloc_id)
-                    .arg("alloc_id", alloc_id)
                     .arg("bad_pointer_message", bad_pointer_message(msg, dcx));
             }
             PointerOutOfBounds { alloc_id, alloc_size, ptr_offset, ptr_size, msg } => {
-                builder
+                diag.arg("alloc_id", alloc_id)
-                    .arg("alloc_id", alloc_id)
                     .arg("alloc_size", alloc_size.bytes())
                     .arg("ptr_offset", ptr_offset)
                     .arg("ptr_size", ptr_size.bytes())
@@ -554,47 +549,47 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
             }
             DanglingIntPointer(ptr, msg) => {
                 if ptr != 0 {
-                    builder.arg("pointer", format!("{ptr:#x}[noalloc]"));
+                    diag.arg("pointer", format!("{ptr:#x}[noalloc]"));
                 }
 
-                builder.arg("bad_pointer_message", bad_pointer_message(msg, dcx));
+                diag.arg("bad_pointer_message", bad_pointer_message(msg, dcx));
             }
             AlignmentCheckFailed(Misalignment { required, has }, msg) => {
-                builder.arg("required", required.bytes());
+                diag.arg("required", required.bytes());
-                builder.arg("has", has.bytes());
+                diag.arg("has", has.bytes());
-                builder.arg("msg", format!("{msg:?}"));
+                diag.arg("msg", format!("{msg:?}"));
             }
             WriteToReadOnly(alloc) | DerefFunctionPointer(alloc) | DerefVTablePointer(alloc) => {
-                builder.arg("allocation", alloc);
+                diag.arg("allocation", alloc);
             }
             InvalidBool(b) => {
-                builder.arg("value", format!("{b:02x}"));
+                diag.arg("value", format!("{b:02x}"));
             }
             InvalidChar(c) => {
-                builder.arg("value", format!("{c:08x}"));
+                diag.arg("value", format!("{c:08x}"));
             }
             InvalidTag(tag) => {
-                builder.arg("tag", format!("{tag:x}"));
+                diag.arg("tag", format!("{tag:x}"));
             }
             InvalidStr(err) => {
-                builder.arg("err", format!("{err}"));
+                diag.arg("err", format!("{err}"));
             }
             InvalidUninitBytes(Some((alloc, info))) => {
-                builder.arg("alloc", alloc);
+                diag.arg("alloc", alloc);
-                builder.arg("access", info.access);
+                diag.arg("access", info.access);
-                builder.arg("uninit", info.bad);
+                diag.arg("uninit", info.bad);
             }
             ScalarSizeMismatch(info) => {
-                builder.arg("target_size", info.target_size);
+                diag.arg("target_size", info.target_size);
-                builder.arg("data_size", info.data_size);
+                diag.arg("data_size", info.data_size);
             }
             InvalidNichedEnumVariantWritten { enum_ty } => {
-                builder.arg("ty", enum_ty.to_string());
+                diag.arg("ty", enum_ty.to_string());
             }
             AbiMismatchArgument { caller_ty, callee_ty }
             | AbiMismatchReturn { caller_ty, callee_ty } => {
-                builder.arg("caller_ty", caller_ty.to_string());
+                diag.arg("caller_ty", caller_ty.to_string());
-                builder.arg("callee_ty", callee_ty.to_string());
+                diag.arg("callee_ty", callee_ty.to_string());
             }
         }
     }
@@ -674,7 +669,7 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
         }
     }
 
-    fn add_args<G: EmissionGuarantee>(self, dcx: &DiagCtxt, err: &mut DiagnosticBuilder<'_, G>) {
+    fn add_args<G: EmissionGuarantee>(self, err: &mut DiagnosticBuilder<'_, G>) {
         use crate::fluent_generated as fluent;
         use rustc_middle::mir::interpret::ValidationErrorKind::*;
 
@@ -684,12 +679,12 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
         }
 
         let message = if let Some(path) = self.path {
-            dcx.eagerly_translate_to_string(
+            err.dcx.eagerly_translate_to_string(
                 fluent::const_eval_validation_front_matter_invalid_value_with_path,
                 [("path".into(), DiagnosticArgValue::Str(path.into()))].iter().map(|(a, b)| (a, b)),
             )
         } else {
-            dcx.eagerly_translate_to_string(
+            err.dcx.eagerly_translate_to_string(
                 fluent::const_eval_validation_front_matter_invalid_value,
                 [].into_iter(),
             )
@@ -700,7 +695,6 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
         fn add_range_arg<G: EmissionGuarantee>(
             r: WrappingRange,
             max_hi: u128,
-            dcx: &DiagCtxt,
             err: &mut DiagnosticBuilder<'_, G>,
         ) {
             let WrappingRange { start: lo, end: hi } = r;
@@ -724,7 +718,7 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
                 ("hi".into(), DiagnosticArgValue::Str(hi.to_string().into())),
             ];
             let args = args.iter().map(|(a, b)| (a, b));
-            let message = dcx.eagerly_translate_to_string(msg, args);
+            let message = err.dcx.eagerly_translate_to_string(msg, args);
             err.arg("in_range", message);
         }
 
@@ -746,7 +740,7 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
                     ExpectedKind::EnumTag => fluent::const_eval_validation_expected_enum_tag,
                     ExpectedKind::Str => fluent::const_eval_validation_expected_str,
                 };
-                let msg = dcx.eagerly_translate_to_string(msg, [].into_iter());
+                let msg = err.dcx.eagerly_translate_to_string(msg, [].into_iter());
                 err.arg("expected", msg);
             }
             InvalidEnumTag { value }
@@ -757,11 +751,11 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
                 err.arg("value", value);
             }
             NullablePtrOutOfRange { range, max_value } | PtrOutOfRange { range, max_value } => {
-                add_range_arg(range, max_value, dcx, err)
+                add_range_arg(range, max_value, err)
             }
             OutOfRange { range, max_value, value } => {
                 err.arg("value", value);
-                add_range_arg(range, max_value, dcx, err);
+                add_range_arg(range, max_value, err);
             }
             UnalignedPtr { required_bytes, found_bytes, .. } => {
                 err.arg("required_bytes", required_bytes);
@@ -802,13 +796,13 @@ impl ReportErrorExt for UnsupportedOpInfo {
             UnsupportedOpInfo::ExternStatic(_) => const_eval_extern_static,
         }
     }
-    fn add_args<G: EmissionGuarantee>(self, _: &DiagCtxt, builder: &mut DiagnosticBuilder<'_, G>) {
+    fn add_args<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>) {
         use crate::fluent_generated::*;
 
         use UnsupportedOpInfo::*;
         if let ReadPointerAsInt(_) | OverwritePartialPointer(_) | ReadPartialPointer(_) = self {
-            builder.help(const_eval_ptr_as_bytes_1);
+            diag.help(const_eval_ptr_as_bytes_1);
-            builder.help(const_eval_ptr_as_bytes_2);
+            diag.help(const_eval_ptr_as_bytes_2);
         }
         match self {
             // `ReadPointerAsInt(Some(info))` is never printed anyway, it only serves as an error to
@@ -816,10 +810,10 @@ impl ReportErrorExt for UnsupportedOpInfo {
             // print. So it's not worth the effort of having diagnostics that can print the `info`.
             UnsizedLocal | Unsupported(_) | ReadPointerAsInt(_) => {}
             OverwritePartialPointer(ptr) | ReadPartialPointer(ptr) => {
-                builder.arg("ptr", ptr);
+                diag.arg("ptr", ptr);
             }
             ThreadLocalStatic(did) | ExternStatic(did) => {
-                builder.arg("did", format!("{did:?}"));
+                diag.arg("did", format!("{did:?}"));
             }
         }
     }
@@ -835,18 +829,14 @@ impl<'tcx> ReportErrorExt for InterpError<'tcx> {
             InterpError::MachineStop(e) => e.diagnostic_message(),
         }
     }
-    fn add_args<G: EmissionGuarantee>(
+    fn add_args<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>) {
-        self,
-        dcx: &DiagCtxt,
-        builder: &mut DiagnosticBuilder<'_, G>,
-    ) {
         match self {
-            InterpError::UndefinedBehavior(ub) => ub.add_args(dcx, builder),
+            InterpError::UndefinedBehavior(ub) => ub.add_args(diag),
-            InterpError::Unsupported(e) => e.add_args(dcx, builder),
+            InterpError::Unsupported(e) => e.add_args(diag),
-            InterpError::InvalidProgram(e) => e.add_args(dcx, builder),
+            InterpError::InvalidProgram(e) => e.add_args(diag),
-            InterpError::ResourceExhaustion(e) => e.add_args(dcx, builder),
+            InterpError::ResourceExhaustion(e) => e.add_args(diag),
             InterpError::MachineStop(e) => e.add_args(&mut |name, value| {
-                builder.arg(name, value);
+                diag.arg(name, value);
             }),
         }
     }
@@ -864,28 +854,24 @@ impl<'tcx> ReportErrorExt for InvalidProgramInfo<'tcx> {
             }
         }
     }
-    fn add_args<G: EmissionGuarantee>(
+    fn add_args<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>) {
-        self,
-        dcx: &DiagCtxt,
-        builder: &mut DiagnosticBuilder<'_, G>,
-    ) {
         match self {
             InvalidProgramInfo::TooGeneric | InvalidProgramInfo::AlreadyReported(_) => {}
             InvalidProgramInfo::Layout(e) => {
-                // The level doesn't matter, `diag` is consumed without it being used.
+                // The level doesn't matter, `dummy_diag` is consumed without it being used.
                 let dummy_level = Level::Bug;
-                let diag: DiagnosticBuilder<'_, ()> =
+                let dummy_diag: DiagnosticBuilder<'_, ()> =
-                    e.into_diagnostic().into_diagnostic(dcx, dummy_level);
+                    e.into_diagnostic().into_diagnostic(diag.dcx, dummy_level);
-                for (name, val) in diag.args() {
+                for (name, val) in dummy_diag.args() {
-                    builder.arg(name.clone(), val.clone());
+                    diag.arg(name.clone(), val.clone());
                 }
-                diag.cancel();
+                dummy_diag.cancel();
             }
             InvalidProgramInfo::FnAbiAdjustForForeignAbi(
                 AdjustForForeignAbiError::Unsupported { arch, abi },
             ) => {
-                builder.arg("arch", arch);
+                diag.arg("arch", arch);
-                builder.arg("abi", abi.name());
+                diag.arg("abi", abi.name());
             }
         }
     }
@@ -900,7 +886,7 @@ impl ReportErrorExt for ResourceExhaustionInfo {
             ResourceExhaustionInfo::AddressSpaceFull => const_eval_address_space_full,
         }
     }
-    fn add_args<G: EmissionGuarantee>(self, _: &DiagCtxt, _: &mut DiagnosticBuilder<'_, G>) {}
+    fn add_args<G: EmissionGuarantee>(self, _: &mut DiagnosticBuilder<'_, G>) {}
 }
 
 impl rustc_errors::IntoDiagnosticArg for InternKind {

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -445,7 +445,7 @@ pub fn format_interp_error<'tcx>(dcx: &DiagCtxt, e: InterpErrorInfo<'tcx>) -> St
     #[allow(rustc::untranslatable_diagnostic)]
     let mut diag = dcx.struct_allow("");
     let msg = e.diagnostic_message();
-    e.add_args(dcx, &mut diag);
+    e.add_args(&mut diag);
     let s = dcx.eagerly_translate_to_string(msg, diag.args());
     diag.cancel();
     s

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -619,9 +619,11 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 if base_ty.is_unsafe_ptr() {
                     if place_ref.projection.is_empty() {
                         let decl = &self.body.local_decls[place_ref.local];
-                        if let LocalInfo::StaticRef { def_id, .. } = *decl.local_info() {
+                        // If this is a static, then this is not really dereferencing a pointer,
-                            let span = decl.source_info.span;
+                        // just directly accessing a static. That is not subject to any feature
-                            self.check_static(def_id, span);
+                        // gates (except for the one about whether statics can even be used, but
+                        // that is checked already by `visit_operand`).
+                        if let LocalInfo::StaticRef { .. } = *decl.local_info() {
                             return;
                         }
                     }

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -409,11 +409,6 @@ impl<'tcx> NonConstOp<'tcx> for TransientCellBorrow {
     fn status_in_item(&self, _: &ConstCx<'_, 'tcx>) -> Status {
         Status::Unstable(sym::const_refs_to_cell)
     }
-    fn importance(&self) -> DiagnosticImportance {
-        // The cases that cannot possibly work will already emit a `CellBorrow`, so we should
-        // not additionally emit a feature gate error if activating the feature gate won't work.
-        DiagnosticImportance::Secondary
-    }
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
         ccx.tcx
             .sess
@@ -427,6 +422,11 @@ impl<'tcx> NonConstOp<'tcx> for TransientCellBorrow {
 /// it in the future for static items.
 pub struct CellBorrow;
 impl<'tcx> NonConstOp<'tcx> for CellBorrow {
+    fn importance(&self) -> DiagnosticImportance {
+        // Most likely the code will try to do mutation with these borrows, which
+        // triggers its own errors. Only show this one if that does not happen.
+        DiagnosticImportance::Secondary
+    }
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
         // FIXME: Maybe a more elegant solution to this if else case
         if let hir::ConstContext::Static(_) = ccx.const_kind() {
@@ -459,8 +459,8 @@ impl<'tcx> NonConstOp<'tcx> for MutBorrow {
     }
 
     fn importance(&self) -> DiagnosticImportance {
-        // If there were primary errors (like non-const function calls), do not emit further
+        // Most likely the code will try to do mutation with these borrows, which
-        // errors about mutable references.
+        // triggers its own errors. Only show this one if that does not happen.
         DiagnosticImportance::Secondary
     }
 

compiler/rustc_const_eval/src/transform/check_consts/resolver.rs

@@ -96,7 +96,7 @@ where
         });
     }
 
-    fn address_of_allows_mutation(&self, _mt: mir::Mutability, _place: mir::Place<'tcx>) -> bool {
+    fn address_of_allows_mutation(&self) -> bool {
         // Exact set of permissions granted by AddressOf is undecided. Conservatively assume that
         // it might allow mutation until resolution of #56604.
         true
@@ -171,10 +171,8 @@ where
         self.super_rvalue(rvalue, location);
 
         match rvalue {
-            mir::Rvalue::AddressOf(mt, borrowed_place) => {
+            mir::Rvalue::AddressOf(_mt, borrowed_place) => {
-                if !borrowed_place.is_indirect()
+                if !borrowed_place.is_indirect() && self.address_of_allows_mutation() {
-                    && self.address_of_allows_mutation(*mt, *borrowed_place)
-                {
                     let place_ty = borrowed_place.ty(self.ccx.body, self.ccx.tcx).ty;
                     if Q::in_any_value_of_ty(self.ccx, place_ty) {
                         self.state.qualif.insert(borrowed_place.local);

compiler/rustc_errors/src/lib.rs

@@ -411,8 +411,8 @@ impl CodeSuggestion {
 /// or `.span_bug` rather than a failed assertion, etc.
 pub struct ExplicitBug;
 
-/// Signifies that the compiler died with an explicit call to `.delay_*_bug`
+/// Signifies that the compiler died due to a delayed bug rather than a failed
-/// rather than a failed assertion, etc.
+/// assertion, etc.
 pub struct DelayedBugPanic;
 
 /// A `DiagCtxt` deals with errors and other compiler output.
@@ -428,10 +428,14 @@ pub struct DiagCtxt {
 struct DiagCtxtInner {
     flags: DiagCtxtFlags,
 
-    /// The number of lint errors that have been emitted, including duplicates.
+    /// The error guarantees from all emitted errors. The length gives the error count.
-    lint_err_count: usize,
+    err_guars: Vec<ErrorGuaranteed>,
-    /// The number of non-lint errors that have been emitted, including duplicates.
+    /// The error guarantee from all emitted lint errors. The length gives the
-    err_count: usize,
+    /// lint error count.
+    lint_err_guars: Vec<ErrorGuaranteed>,
+    /// The delayed bugs and their error guarantees.
+    delayed_bugs: Vec<(DelayedDiagnostic, ErrorGuaranteed)>,
+    good_path_delayed_bugs: Vec<DelayedDiagnostic>,
 
     /// The number of stashed errors. Unlike the other counts, this can go up
     /// and down, so it doesn't guarantee anything.
@@ -447,8 +451,6 @@ struct DiagCtxtInner {
     has_printed: bool,
 
     emitter: Box<DynEmitter>,
-    delayed_bugs: Vec<DelayedDiagnostic>,
-    good_path_delayed_bugs: Vec<DelayedDiagnostic>,
     /// This flag indicates that an expected diagnostic was emitted and suppressed.
     /// This is used for the `good_path_delayed_bugs` check.
     suppressed_expected_diag: bool,
@@ -560,7 +562,7 @@ impl Drop for DiagCtxtInner {
     fn drop(&mut self) {
         self.emit_stashed_diagnostics();
 
-        if !self.has_errors() {
+        if self.err_guars.is_empty() {
             self.flush_delayed(DelayedBugKind::Normal)
         }
 
@@ -604,15 +606,15 @@ impl DiagCtxt {
         Self {
             inner: Lock::new(DiagCtxtInner {
                 flags: DiagCtxtFlags { can_emit_warnings: true, ..Default::default() },
-                lint_err_count: 0,
+                err_guars: Vec::new(),
-                err_count: 0,
+                lint_err_guars: Vec::new(),
+                delayed_bugs: Vec::new(),
+                good_path_delayed_bugs: Vec::new(),
                 stashed_err_count: 0,
                 deduplicated_err_count: 0,
                 deduplicated_warn_count: 0,
                 has_printed: false,
                 emitter,
-                delayed_bugs: Vec::new(),
-                good_path_delayed_bugs: Vec::new(),
                 suppressed_expected_diag: false,
                 taught_diagnostics: Default::default(),
                 emitted_diagnostic_codes: Default::default(),
@@ -661,14 +663,14 @@ impl DiagCtxt {
     /// the overall count of emitted error diagnostics.
     pub fn reset_err_count(&self) {
         let mut inner = self.inner.borrow_mut();
-        inner.lint_err_count = 0;
-        inner.err_count = 0;
         inner.stashed_err_count = 0;
         inner.deduplicated_err_count = 0;
         inner.deduplicated_warn_count = 0;
         inner.has_printed = false;
 
         // actually free the underlying memory (which `clear` would not do)
+        inner.err_guars = Default::default();
+        inner.lint_err_guars = Default::default();
         inner.delayed_bugs = Default::default();
         inner.good_path_delayed_bugs = Default::default();
         inner.taught_diagnostics = Default::default();
@@ -718,221 +720,10 @@ impl DiagCtxt {
         self.inner.borrow_mut().emit_stashed_diagnostics()
     }
 
-    /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
-    ///
-    /// An `emit` call on the builder will only emit if `can_emit_warnings` is `true`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_span_warn(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_, ()> {
-        self.struct_warn(msg).with_span(span)
-    }
-
-    /// Construct a builder at the `Warning` level with the `msg`.
-    ///
-    /// An `emit` call on the builder will only emit if `can_emit_warnings` is `true`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Warning, msg)
-    }
-
-    /// Construct a builder at the `Allow` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_allow(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Allow, msg)
-    }
-
-    /// Construct a builder at the `Expect` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_expect(
-        &self,
-        msg: impl Into<DiagnosticMessage>,
-        id: LintExpectationId,
-    ) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Expect(id), msg)
-    }
-
-    /// Construct a builder at the `Error` level at the given `span` and with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_span_err(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_> {
-        self.struct_err(msg).with_span(span)
-    }
-
-    /// Construct a builder at the `Error` level with the `msg`.
-    // FIXME: This method should be removed (every error should have an associated error code).
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_err(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_> {
-        DiagnosticBuilder::new(self, Error, msg)
-    }
-
-    /// Construct a builder at the `Fatal` level at the given `span` and with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_span_fatal(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_, FatalAbort> {
-        self.struct_fatal(msg).with_span(span)
-    }
-
-    /// Construct a builder at the `Fatal` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_fatal(
-        &self,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_, FatalAbort> {
-        DiagnosticBuilder::new(self, Fatal, msg)
-    }
-
-    /// Construct a builder at the `Help` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    pub fn struct_help(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Help, msg)
-    }
-
-    /// Construct a builder at the `Note` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_note(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Note, msg)
-    }
-
-    /// Construct a builder at the `Bug` level with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_bug(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, BugAbort> {
-        DiagnosticBuilder::new(self, Bug, msg)
-    }
-
-    /// Construct a builder at the `Bug` level at the given `span` with the `msg`.
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn struct_span_bug(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_, BugAbort> {
-        self.struct_bug(msg).with_span(span)
-    }
-
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
-        self.struct_span_fatal(span, msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn span_err(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> ErrorGuaranteed {
-        self.struct_span_err(span, msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    #[track_caller]
-    pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
-        self.struct_span_warn(span, msg).emit()
-    }
-
-    #[track_caller]
-    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
-        self.struct_span_bug(span, msg).emit()
-    }
-
-    /// Ensures that compilation cannot succeed.
-    ///
-    /// If this function has been called but no errors have been emitted and
-    /// compilation succeeds, it will cause an internal compiler error (ICE).
-    ///
-    /// This can be used in code paths that should never run on successful compilations.
-    /// For example, it can be used to create an [`ErrorGuaranteed`]
-    /// (but you should prefer threading through the [`ErrorGuaranteed`] from an error emission
-    /// directly).
-    #[track_caller]
-    pub fn delayed_bug(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
-        DiagnosticBuilder::<ErrorGuaranteed>::new(self, DelayedBug, msg).emit()
-    }
-
-    /// Like `delayed_bug`, but takes an additional span.
-    ///
-    /// Note: this function used to be called `delay_span_bug`. It was renamed
-    /// to match similar functions like `span_err`, `span_warn`, etc.
-    #[track_caller]
-    pub fn span_delayed_bug(
-        &self,
-        sp: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> ErrorGuaranteed {
-        DiagnosticBuilder::<ErrorGuaranteed>::new(self, DelayedBug, msg).with_span(sp).emit()
-    }
-
-    /// Ensures that a diagnostic is printed. See `Level::GoodPathDelayedBug`.
-    pub fn good_path_delayed_bug(&self, msg: impl Into<DiagnosticMessage>) {
-        DiagnosticBuilder::<()>::new(self, GoodPathDelayedBug, msg).emit()
-    }
-
-    #[track_caller]
-    #[rustc_lint_diagnostics]
-    pub fn span_note(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
-        self.struct_span_note(span, msg).emit()
-    }
-
-    #[track_caller]
-    #[rustc_lint_diagnostics]
-    pub fn struct_span_note(
-        &self,
-        span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
-    ) -> DiagnosticBuilder<'_, ()> {
-        DiagnosticBuilder::new(self, Note, msg).with_span(span)
-    }
-
-    #[rustc_lint_diagnostics]
-    pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> ! {
-        self.struct_fatal(msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
-        self.struct_err(msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
-        self.struct_warn(msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    pub fn note(&self, msg: impl Into<DiagnosticMessage>) {
-        self.struct_note(msg).emit()
-    }
-
-    #[rustc_lint_diagnostics]
-    pub fn bug(&self, msg: impl Into<DiagnosticMessage>) -> ! {
-        self.struct_bug(msg).emit()
-    }
-
     /// This excludes lint errors, delayed bugs, and stashed errors.
     #[inline]
     pub fn err_count(&self) -> usize {
-        self.inner.borrow().err_count
+        self.inner.borrow().err_guars.len()
     }
 
     /// This excludes normal errors, lint errors and delayed bugs. Unless
@@ -946,36 +737,19 @@ impl DiagCtxt {
 
     /// This excludes lint errors, delayed bugs, and stashed errors.
     pub fn has_errors(&self) -> Option<ErrorGuaranteed> {
-        self.inner.borrow().has_errors().then(|| {
+        self.inner.borrow().has_errors()
-            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
-            #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_error_guaranteed()
-        })
     }
 
     /// This excludes delayed bugs and stashed errors. Unless absolutely
     /// necessary, prefer `has_errors` to this method.
     pub fn has_errors_or_lint_errors(&self) -> Option<ErrorGuaranteed> {
-        let inner = self.inner.borrow();
+        self.inner.borrow().has_errors_or_lint_errors()
-        let result = inner.has_errors() || inner.lint_err_count > 0;
-        result.then(|| {
-            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
-            #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_error_guaranteed()
-        })
     }
 
     /// This excludes stashed errors. Unless absolutely necessary, prefer
     /// `has_errors` or `has_errors_or_lint_errors` to this method.
     pub fn has_errors_or_lint_errors_or_delayed_bugs(&self) -> Option<ErrorGuaranteed> {
-        let inner = self.inner.borrow();
+        self.inner.borrow().has_errors_or_lint_errors_or_delayed_bugs()
-        let result =
-            inner.has_errors() || inner.lint_err_count > 0 || !inner.delayed_bugs.is_empty();
-        result.then(|| {
-            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
-            #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_error_guaranteed()
-        })
     }
 
     pub fn print_error_count(&self, registry: &Registry) {
@@ -1008,10 +782,10 @@ impl DiagCtxt {
                     .emit_diagnostic(Diagnostic::new(Warning, DiagnosticMessage::Str(warnings)));
             }
             (_, 0) => {
-                inner.emit_diagnostic(Diagnostic::new(Fatal, errors));
+                inner.emit_diagnostic(Diagnostic::new(Error, errors));
             }
             (_, _) => {
-                inner.emit_diagnostic(Diagnostic::new(Fatal, format!("{errors}; {warnings}")));
+                inner.emit_diagnostic(Diagnostic::new(Error, format!("{errors}; {warnings}")));
             }
         }
 
@@ -1055,7 +829,7 @@ impl DiagCtxt {
     pub fn abort_if_errors(&self) {
         let mut inner = self.inner.borrow_mut();
         inner.emit_stashed_diagnostics();
-        if inner.has_errors() {
+        if !inner.err_guars.is_empty() {
             FatalError.raise();
         }
     }
@@ -1077,84 +851,6 @@ impl DiagCtxt {
         self.inner.borrow_mut().emit_diagnostic(diagnostic)
     }
 
-    #[track_caller]
-    pub fn emit_err<'a>(&'a self, err: impl IntoDiagnostic<'a>) -> ErrorGuaranteed {
-        self.create_err(err).emit()
-    }
-
-    #[track_caller]
-    pub fn create_err<'a>(&'a self, err: impl IntoDiagnostic<'a>) -> DiagnosticBuilder<'a> {
-        err.into_diagnostic(self, Error)
-    }
-
-    #[track_caller]
-    pub fn create_warn<'a>(
-        &'a self,
-        warning: impl IntoDiagnostic<'a, ()>,
-    ) -> DiagnosticBuilder<'a, ()> {
-        warning.into_diagnostic(self, Warning)
-    }
-
-    #[track_caller]
-    pub fn emit_warn<'a>(&'a self, warning: impl IntoDiagnostic<'a, ()>) {
-        self.create_warn(warning).emit()
-    }
-
-    #[track_caller]
-    pub fn create_almost_fatal<'a>(
-        &'a self,
-        fatal: impl IntoDiagnostic<'a, FatalError>,
-    ) -> DiagnosticBuilder<'a, FatalError> {
-        fatal.into_diagnostic(self, Fatal)
-    }
-
-    #[track_caller]
-    pub fn emit_almost_fatal<'a>(
-        &'a self,
-        fatal: impl IntoDiagnostic<'a, FatalError>,
-    ) -> FatalError {
-        self.create_almost_fatal(fatal).emit()
-    }
-
-    #[track_caller]
-    pub fn create_fatal<'a>(
-        &'a self,
-        fatal: impl IntoDiagnostic<'a, FatalAbort>,
-    ) -> DiagnosticBuilder<'a, FatalAbort> {
-        fatal.into_diagnostic(self, Fatal)
-    }
-
-    #[track_caller]
-    pub fn emit_fatal<'a>(&'a self, fatal: impl IntoDiagnostic<'a, FatalAbort>) -> ! {
-        self.create_fatal(fatal).emit()
-    }
-
-    #[track_caller]
-    pub fn create_bug<'a>(
-        &'a self,
-        bug: impl IntoDiagnostic<'a, BugAbort>,
-    ) -> DiagnosticBuilder<'a, BugAbort> {
-        bug.into_diagnostic(self, Bug)
-    }
-
-    #[track_caller]
-    pub fn emit_bug<'a>(&'a self, bug: impl IntoDiagnostic<'a, diagnostic_builder::BugAbort>) -> ! {
-        self.create_bug(bug).emit()
-    }
-
-    #[track_caller]
-    pub fn emit_note<'a>(&'a self, note: impl IntoDiagnostic<'a, ()>) {
-        self.create_note(note).emit()
-    }
-
-    #[track_caller]
-    pub fn create_note<'a>(
-        &'a self,
-        note: impl IntoDiagnostic<'a, ()>,
-    ) -> DiagnosticBuilder<'a, ()> {
-        note.into_diagnostic(self, Note)
-    }
-
     pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
         self.inner.borrow_mut().emitter.emit_artifact_notification(path, artifact_type);
     }
@@ -1175,8 +871,21 @@ impl DiagCtxt {
     ) {
         let mut inner = self.inner.borrow_mut();
 
+        // This "error" is an odd duck.
+        // - It's only produce with JSON output.
+        // - It's not emitted the usual way, via `emit_diagnostic`.
+        // - The `$message_type` field is "unused_externs" rather than the usual
+        //   "diagnosic".
+        //
+        // We count it as a lint error because it has a lint level. The value
+        // of `loud` (which comes from "unused-externs" or
+        // "unused-externs-silent"), also affects whether it's treated like a
+        // hard error or not.
         if loud && lint_level.is_error() {
-            inner.lint_err_count += 1;
+            // This `unchecked_error_guaranteed` is valid. It is where the
+            // `ErrorGuaranteed` for unused_extern errors originates.
+            #[allow(deprecated)]
+            inner.lint_err_guars.push(ErrorGuaranteed::unchecked_error_guaranteed());
             inner.panic_if_treat_err_as_bug();
         }
 
@@ -1229,6 +938,288 @@ impl DiagCtxt {
     }
 }
 
+// This `impl` block contains only the public diagnostic creation/emission API.
+//
+// Functions beginning with `struct_`/`create_` create a diagnostic. Other
+// functions create and emit a diagnostic all in one go.
+impl DiagCtxt {
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn struct_bug(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, BugAbort> {
+        DiagnosticBuilder::new(self, Bug, msg)
+    }
+
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn bug(&self, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.struct_bug(msg).emit()
+    }
+
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn struct_span_bug(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, BugAbort> {
+        self.struct_bug(msg).with_span(span)
+    }
+
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.struct_span_bug(span, msg).emit()
+    }
+
+    #[track_caller]
+    pub fn create_bug<'a>(
+        &'a self,
+        bug: impl IntoDiagnostic<'a, BugAbort>,
+    ) -> DiagnosticBuilder<'a, BugAbort> {
+        bug.into_diagnostic(self, Bug)
+    }
+
+    #[track_caller]
+    pub fn emit_bug<'a>(&'a self, bug: impl IntoDiagnostic<'a, BugAbort>) -> ! {
+        self.create_bug(bug).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_fatal(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, FatalAbort> {
+        DiagnosticBuilder::new(self, Fatal, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.struct_fatal(msg).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_span_fatal(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, FatalAbort> {
+        self.struct_fatal(msg).with_span(span)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+        self.struct_span_fatal(span, msg).emit()
+    }
+
+    #[track_caller]
+    pub fn create_fatal<'a>(
+        &'a self,
+        fatal: impl IntoDiagnostic<'a, FatalAbort>,
+    ) -> DiagnosticBuilder<'a, FatalAbort> {
+        fatal.into_diagnostic(self, Fatal)
+    }
+
+    #[track_caller]
+    pub fn emit_fatal<'a>(&'a self, fatal: impl IntoDiagnostic<'a, FatalAbort>) -> ! {
+        self.create_fatal(fatal).emit()
+    }
+
+    #[track_caller]
+    pub fn create_almost_fatal<'a>(
+        &'a self,
+        fatal: impl IntoDiagnostic<'a, FatalError>,
+    ) -> DiagnosticBuilder<'a, FatalError> {
+        fatal.into_diagnostic(self, Fatal)
+    }
+
+    #[track_caller]
+    pub fn emit_almost_fatal<'a>(
+        &'a self,
+        fatal: impl IntoDiagnostic<'a, FatalError>,
+    ) -> FatalError {
+        self.create_almost_fatal(fatal).emit()
+    }
+
+    // FIXME: This method should be removed (every error should have an associated error code).
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_err(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_> {
+        DiagnosticBuilder::new(self, Error, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+        self.struct_err(msg).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_span_err(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_> {
+        self.struct_err(msg).with_span(span)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn span_err(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> ErrorGuaranteed {
+        self.struct_span_err(span, msg).emit()
+    }
+
+    #[track_caller]
+    pub fn create_err<'a>(&'a self, err: impl IntoDiagnostic<'a>) -> DiagnosticBuilder<'a> {
+        err.into_diagnostic(self, Error)
+    }
+
+    #[track_caller]
+    pub fn emit_err<'a>(&'a self, err: impl IntoDiagnostic<'a>) -> ErrorGuaranteed {
+        self.create_err(err).emit()
+    }
+
+    /// Ensures that an error is printed. See `Level::DelayedBug`.
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn delayed_bug(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+        DiagnosticBuilder::<ErrorGuaranteed>::new(self, DelayedBug, msg).emit()
+    }
+
+    /// Ensures that an error is printed. See `Level::DelayedBug`.
+    ///
+    /// Note: this function used to be called `delay_span_bug`. It was renamed
+    /// to match similar functions like `span_err`, `span_warn`, etc.
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn span_delayed_bug(
+        &self,
+        sp: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> ErrorGuaranteed {
+        DiagnosticBuilder::<ErrorGuaranteed>::new(self, DelayedBug, msg).with_span(sp).emit()
+    }
+
+    /// Ensures that a diagnostic is printed. See `Level::GoodPathDelayedBug`.
+    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    #[track_caller]
+    pub fn good_path_delayed_bug(&self, msg: impl Into<DiagnosticMessage>) {
+        DiagnosticBuilder::<()>::new(self, GoodPathDelayedBug, msg).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Warning, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
+        self.struct_warn(msg).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_span_warn(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, ()> {
+        self.struct_warn(msg).with_span(span)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+        self.struct_span_warn(span, msg).emit()
+    }
+
+    #[track_caller]
+    pub fn create_warn<'a>(
+        &'a self,
+        warning: impl IntoDiagnostic<'a, ()>,
+    ) -> DiagnosticBuilder<'a, ()> {
+        warning.into_diagnostic(self, Warning)
+    }
+
+    #[track_caller]
+    pub fn emit_warn<'a>(&'a self, warning: impl IntoDiagnostic<'a, ()>) {
+        self.create_warn(warning).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_note(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Note, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn note(&self, msg: impl Into<DiagnosticMessage>) {
+        self.struct_note(msg).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_span_note(
+        &self,
+        span: impl Into<MultiSpan>,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Note, msg).with_span(span)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn span_note(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+        self.struct_span_note(span, msg).emit()
+    }
+
+    #[track_caller]
+    pub fn create_note<'a>(
+        &'a self,
+        note: impl IntoDiagnostic<'a, ()>,
+    ) -> DiagnosticBuilder<'a, ()> {
+        note.into_diagnostic(self, Note)
+    }
+
+    #[track_caller]
+    pub fn emit_note<'a>(&'a self, note: impl IntoDiagnostic<'a, ()>) {
+        self.create_note(note).emit()
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_help(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Help, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_allow(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Allow, msg)
+    }
+
+    #[rustc_lint_diagnostics]
+    #[track_caller]
+    pub fn struct_expect(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+        id: LintExpectationId,
+    ) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Expect(id), msg)
+    }
+}
+
 // Note: we prefer implementing operations on `DiagCtxt`, rather than
 // `DiagCtxtInner`, whenever possible. This minimizes functions where
 // `DiagCtxt::foo()` just borrows `inner` and forwards a call to
@@ -1236,7 +1227,7 @@ impl DiagCtxt {
 impl DiagCtxtInner {
     /// Emit all stashed diagnostics.
     fn emit_stashed_diagnostics(&mut self) {
-        let has_errors = self.has_errors();
+        let has_errors = !self.err_guars.is_empty();
         for (_, diag) in std::mem::take(&mut self.stashed_diagnostics).into_iter() {
             // Decrement the count tracking the stash; emitting will increment it.
             if diag.is_error() {
@@ -1298,9 +1289,13 @@ impl DiagCtxtInner {
                 // when an error is first emitted, also), but maybe there's a case
                 // in which that's not sound? otherwise this is really inefficient.
                 let backtrace = std::backtrace::Backtrace::capture();
-                self.delayed_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace));
+                // This `unchecked_error_guaranteed` is valid. It is where the
+                // `ErrorGuaranteed` for delayed bugs originates.
                 #[allow(deprecated)]
-                return Some(ErrorGuaranteed::unchecked_error_guaranteed());
+                let guar = ErrorGuaranteed::unchecked_error_guaranteed();
+                self.delayed_bugs
+                    .push((DelayedDiagnostic::with_backtrace(diagnostic, backtrace), guar));
+                return Some(guar);
             }
             GoodPathDelayedBug => {
                 let backtrace = std::backtrace::Backtrace::capture();
@@ -1334,7 +1329,6 @@ impl DiagCtxtInner {
                 !self.emitted_diagnostics.insert(diagnostic_hash)
             };
 
-            let level = diagnostic.level;
             let is_error = diagnostic.is_error();
             let is_lint = diagnostic.is_lint.is_some();
 
@@ -1373,36 +1367,47 @@ impl DiagCtxtInner {
             }
 
             if is_error {
+                // This `unchecked_error_guaranteed` is valid. It is where the
+                // `ErrorGuaranteed` for errors and lint errors originates.
+                #[allow(deprecated)]
+                let guar = ErrorGuaranteed::unchecked_error_guaranteed();
+                guaranteed = Some(guar);
                 if is_lint {
-                    self.lint_err_count += 1;
+                    self.lint_err_guars.push(guar);
                 } else {
-                    self.err_count += 1;
+                    self.err_guars.push(guar);
                 }
                 self.panic_if_treat_err_as_bug();
             }
-
-            #[allow(deprecated)]
-            if level == Level::Error {
-                guaranteed = Some(ErrorGuaranteed::unchecked_error_guaranteed());
-            }
         });
 
         guaranteed
     }
 
     fn treat_err_as_bug(&self) -> bool {
-        self.flags.treat_err_as_bug.is_some_and(|c| self.err_count + self.lint_err_count >= c.get())
+        self.flags
+            .treat_err_as_bug
+            .is_some_and(|c| self.err_guars.len() + self.lint_err_guars.len() >= c.get())
     }
 
     // Use this one before incrementing `err_count`.
     fn treat_next_err_as_bug(&self) -> bool {
         self.flags
             .treat_err_as_bug
-            .is_some_and(|c| self.err_count + self.lint_err_count + 1 >= c.get())
+            .is_some_and(|c| self.err_guars.len() + self.lint_err_guars.len() + 1 >= c.get())
     }
 
-    fn has_errors(&self) -> bool {
+    fn has_errors(&self) -> Option<ErrorGuaranteed> {
-        self.err_count > 0
+        self.err_guars.get(0).copied()
+    }
+
+    fn has_errors_or_lint_errors(&self) -> Option<ErrorGuaranteed> {
+        self.has_errors().or_else(|| self.lint_err_guars.get(0).copied())
+    }
+
+    fn has_errors_or_lint_errors_or_delayed_bugs(&self) -> Option<ErrorGuaranteed> {
+        self.has_errors_or_lint_errors()
+            .or_else(|| self.delayed_bugs.get(0).map(|(_, guar)| guar).copied())
     }
 
     fn failure_note(&mut self, msg: impl Into<DiagnosticMessage>) {
@@ -1412,7 +1417,7 @@ impl DiagCtxtInner {
     fn flush_delayed(&mut self, kind: DelayedBugKind) {
         let (bugs, note1) = match kind {
             DelayedBugKind::Normal => (
-                std::mem::take(&mut self.delayed_bugs),
+                std::mem::take(&mut self.delayed_bugs).into_iter().map(|(b, _)| b).collect(),
                 "no errors encountered even though delayed bugs were created",
             ),
             DelayedBugKind::GoodPath => (
@@ -1434,7 +1439,7 @@ impl DiagCtxtInner {
             {
                 let _ = write!(
                     &mut out,
-                    "delayed span bug: {}\n{}\n",
+                    "delayed bug: {}\n{}\n",
                     bug.inner
                         .messages
                         .iter()
@@ -1477,7 +1482,7 @@ impl DiagCtxtInner {
     fn panic_if_treat_err_as_bug(&self) {
         if self.treat_err_as_bug() {
             let n = self.flags.treat_err_as_bug.map(|c| c.get()).unwrap();
-            assert_eq!(n, self.err_count + self.lint_err_count);
+            assert_eq!(n, self.err_guars.len() + self.lint_err_guars.len());
             if n == 1 {
                 panic!("aborting due to `-Z treat-err-as-bug=1`");
             } else {
@@ -1584,6 +1589,7 @@ pub enum Level {
     ForceWarning(Option<LintExpectationId>),
 
     /// A warning about the code being compiled. Does not prevent compilation from finishing.
+    /// Will be skipped if `can_emit_warnings` is false.
     Warning,
 
     /// A message giving additional context.

compiler/rustc_feature/src/builtin_attrs.rs

@@ -806,7 +806,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     rustc_attr!(TEST, rustc_regions, Normal, template!(Word), WarnFollowing),
     rustc_attr!(
         TEST, rustc_error, Normal,
-        template!(Word, List: "span_delayed_bug_from_inside_query"), WarnFollowingWordOnly
+        template!(Word, List: "delayed_bug_from_inside_query"), WarnFollowingWordOnly
     ),
     rustc_attr!(TEST, rustc_dump_user_args, Normal, template!(Word), WarnFollowing),
     rustc_attr!(TEST, rustc_evaluate_where_clauses, Normal, template!(Word), WarnFollowing),

compiler/rustc_hir_analysis/src/autoderef.rs

@@ -91,10 +91,6 @@ impl<'a, 'tcx> Iterator for Autoderef<'a, 'tcx> {
             return None;
         };
 
-        if new_ty.references_error() {
-            return None;
-        }
-
         self.state.steps.push((self.state.cur_ty, kind));
         debug!(
             "autoderef stage #{:?} is {:?} from {:?}",
@@ -137,6 +133,10 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
         debug!("overloaded_deref_ty({:?})", ty);
         let tcx = self.infcx.tcx;
 
+        if ty.references_error() {
+            return None;
+        }
+
         // <ty as Deref>
         let trait_ref = ty::TraitRef::new(tcx, tcx.lang_items().deref_trait()?, [ty]);
         let cause = traits::ObligationCause::misc(self.span, self.body_id);

compiler/rustc_hir_analysis/src/check/region.rs

@@ -16,7 +16,6 @@ use rustc_index::Idx;
 use rustc_middle::middle::region::*;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::source_map;
-use rustc_span::Span;
 
 use super::errs::{maybe_expr_static_mut, maybe_stmt_static_mut};
 
@@ -72,11 +71,7 @@ struct RegionResolutionVisitor<'tcx> {
 }
 
 /// Records the lifetime of a local variable as `cx.var_parent`
-fn record_var_lifetime(
+fn record_var_lifetime(visitor: &mut RegionResolutionVisitor<'_>, var_id: hir::ItemLocalId) {
-    visitor: &mut RegionResolutionVisitor<'_>,
-    var_id: hir::ItemLocalId,
-    _sp: Span,
-) {
     match visitor.cx.var_parent {
         None => {
             // this can happen in extern fn declarations like
@@ -210,7 +205,7 @@ fn resolve_pat<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, pat: &'tcx hir
 
     // If this is a binding then record the lifetime of that binding.
     if let PatKind::Binding(..) = pat.kind {
-        record_var_lifetime(visitor, pat.hir_id.local_id, pat.span);
+        record_var_lifetime(visitor, pat.hir_id.local_id);
     }
 
     debug!("resolve_pat - pre-increment {} pat = {:?}", visitor.expr_and_pat_count, pat);

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -118,9 +118,9 @@ where
             return Err(err);
         } else {
             // HACK(oli-obk): tests/ui/specialization/min_specialization/specialize_on_type_error.rs
-            // causes an error (span_delayed_bug) during normalization, without reporting an error,
+            // causes an delayed bug during normalization, without reporting an error, so we need
-            // so we need to act as if no error happened, in order to let our callers continue and
+            // to act as if no error happened, in order to let our callers continue and report an
-            // report an error later in check_impl_items_against_trait.
+            // error later in check_impl_items_against_trait.
             return Ok(());
         }
     }
@@ -1635,6 +1635,12 @@ fn check_method_receiver<'tcx>(
     let receiver_ty = sig.inputs()[0];
     let receiver_ty = wfcx.normalize(span, None, receiver_ty);
 
+    // If the receiver already has errors reported, consider it valid to avoid
+    // unnecessary errors (#58712).
+    if receiver_ty.references_error() {
+        return Ok(());
+    }
+
     if tcx.features().arbitrary_self_types {
         if !receiver_is_valid(wfcx, span, receiver_ty, self_ty, true) {
             // Report error; `arbitrary_self_types` was enabled.
@@ -1749,9 +1755,7 @@ fn receiver_is_valid<'tcx>(
             }
         } else {
             debug!("receiver_is_valid: type `{:?}` does not deref to `{:?}`", receiver_ty, self_ty);
-            // If the receiver already has errors reported due to it, consider it valid to avoid
+            return false;
-            // unnecessary errors (#58712).
-            return receiver_ty.references_error();
         }
     }
 

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -425,9 +425,7 @@ fn check_predicates<'tcx>(
 
     let mut res = Ok(());
     for (clause, span) in impl1_predicates {
-        if !impl2_predicates
+        if !impl2_predicates.iter().any(|pred2| trait_predicates_eq(clause.as_predicate(), *pred2))
-            .iter()
-            .any(|pred2| trait_predicates_eq(tcx, clause.as_predicate(), *pred2, span))
         {
             res = res.and(check_specialization_on(tcx, clause, span))
         }
@@ -459,10 +457,8 @@ fn check_predicates<'tcx>(
 ///
 /// So we make that check in this function and try to raise a helpful error message.
 fn trait_predicates_eq<'tcx>(
-    _tcx: TyCtxt<'tcx>,
     predicate1: ty::Predicate<'tcx>,
     predicate2: ty::Predicate<'tcx>,
-    _span: Span,
 ) -> bool {
     // FIXME(effects)
     predicate1 == predicate2

compiler/rustc_hir_typeck/src/expr.rs

@@ -346,7 +346,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             ExprKind::DropTemps(e) => self.check_expr_with_expectation(e, expected),
             ExprKind::Array(args) => self.check_expr_array(args, expected, expr),
-            ExprKind::ConstBlock(ref block) => self.check_expr_const_block(block, expected, expr),
+            ExprKind::ConstBlock(ref block) => self.check_expr_const_block(block, expected),
             ExprKind::Repeat(element, ref count) => {
                 self.check_expr_repeat(element, count, expected, expr)
             }
@@ -1487,7 +1487,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         block: &'tcx hir::ConstBlock,
         expected: Expectation<'tcx>,
-        _expr: &'tcx hir::Expr<'tcx>,
     ) -> Ty<'tcx> {
         let body = self.tcx.hir().body(block.body);
 

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -142,7 +142,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
             let param_ty = return_if_err!(self.mc.pat_ty_adjusted(param.pat));
             debug!("consume_body: param_ty = {:?}", param_ty);
 
-            let param_place = self.mc.cat_rvalue(param.hir_id, param.pat.span, param_ty);
+            let param_place = self.mc.cat_rvalue(param.hir_id, param_ty);
 
             self.walk_irrefutable_pat(&param_place, param.pat);
         }

compiler/rustc_hir_typeck/src/mem_categorization.rs

@@ -273,7 +273,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
                         deref.region,
                         ty::TypeAndMut { ty: target, mutbl: deref.mutbl },
                     );
-                    self.cat_rvalue(expr.hir_id, expr.span, ref_ty)
+                    self.cat_rvalue(expr.hir_id, ref_ty)
                 } else {
                     previous()?
                 };
@@ -285,7 +285,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
             | adjustment::Adjust::Borrow(_)
             | adjustment::Adjust::DynStar => {
                 // Result is an rvalue.
-                Ok(self.cat_rvalue(expr.hir_id, expr.span, target))
+                Ok(self.cat_rvalue(expr.hir_id, target))
             }
         }
     }
@@ -374,7 +374,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
             | hir::ExprKind::Repeat(..)
             | hir::ExprKind::InlineAsm(..)
             | hir::ExprKind::OffsetOf(..)
-            | hir::ExprKind::Err(_) => Ok(self.cat_rvalue(expr.hir_id, expr.span, expr_ty)),
+            | hir::ExprKind::Err(_) => Ok(self.cat_rvalue(expr.hir_id, expr_ty)),
         }
     }
 
@@ -396,7 +396,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
                 | DefKind::AssocFn,
                 _,
             )
-            | Res::SelfCtor(..) => Ok(self.cat_rvalue(hir_id, span, expr_ty)),
+            | Res::SelfCtor(..) => Ok(self.cat_rvalue(hir_id, expr_ty)),
 
             Res::Def(DefKind::Static(_), _) => {
                 Ok(PlaceWithHirId::new(hir_id, expr_ty, PlaceBase::StaticItem, Vec::new()))
@@ -433,13 +433,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
     }
 
     #[instrument(level = "debug", skip(self), ret)]
-    pub(crate) fn cat_rvalue(
+    pub(crate) fn cat_rvalue(&self, hir_id: hir::HirId, expr_ty: Ty<'tcx>) -> PlaceWithHirId<'tcx> {
-        &self,
-        hir_id: hir::HirId,
-        // FIXME: remove
-        _span: Span,
-        expr_ty: Ty<'tcx>,
-    ) -> PlaceWithHirId<'tcx> {
         PlaceWithHirId::new(hir_id, expr_ty, PlaceBase::Rvalue, Vec::new())
     }
 
@@ -487,7 +481,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
         };
         let ref_ty = Ty::new_ref(self.tcx(), region, ty::TypeAndMut { ty: place_ty, mutbl });
 
-        let base = self.cat_rvalue(expr.hir_id, expr.span, ref_ty);
+        let base = self.cat_rvalue(expr.hir_id, ref_ty);
         self.cat_deref(expr, base)
     }
 

compiler/rustc_infer/src/infer/canonical/canonicalizer.rs

@@ -191,7 +191,7 @@ impl CanonicalizeMode for CanonicalizeQueryResponse {
                 //
                 // rust-lang/rust#57464: `impl Trait` can leak local
                 // scopes (in manner violating typeck). Therefore, use
-                // `span_delayed_bug` to allow type error over an ICE.
+                // `delayed_bug` to allow type error over an ICE.
                 canonicalizer
                     .tcx
                     .dcx()

compiler/rustc_interface/src/queries.rs

@@ -194,16 +194,16 @@ impl<'tcx> Queries<'tcx> {
         let Some((def_id, _)) = tcx.entry_fn(()) else { return };
         for attr in tcx.get_attrs(def_id, sym::rustc_error) {
             match attr.meta_item_list() {
-                // Check if there is a `#[rustc_error(span_delayed_bug_from_inside_query)]`.
+                // Check if there is a `#[rustc_error(delayed_bug_from_inside_query)]`.
                 Some(list)
                     if list.iter().any(|list_item| {
                         matches!(
                             list_item.ident().map(|i| i.name),
-                            Some(sym::span_delayed_bug_from_inside_query)
+                            Some(sym::delayed_bug_from_inside_query)
                         )
                     }) =>
                 {
-                    tcx.ensure().trigger_span_delayed_bug(def_id);
+                    tcx.ensure().trigger_delayed_bug(def_id);
                 }
 
                 // Bare `#[rustc_error]`.

compiler/rustc_middle/src/query/mod.rs

@@ -108,9 +108,9 @@ pub use plumbing::{IntoQueryParam, TyCtxtAt, TyCtxtEnsure, TyCtxtEnsureWithValue
 // Queries marked with `fatal_cycle` do not need the latter implementation,
 // as they will raise an fatal error on query cycles instead.
 rustc_queries! {
-    /// This exists purely for testing the interactions between span_delayed_bug and incremental.
+    /// This exists purely for testing the interactions between delayed bugs and incremental.
-    query trigger_span_delayed_bug(key: DefId) {
+    query trigger_delayed_bug(key: DefId) {
-        desc { "triggering a span delayed bug for testing incremental" }
+        desc { "triggering a delayed bug for testing incremental" }
     }
 
     /// Collects the list of all tools registered using `#![register_tool]`.

compiler/rustc_middle/src/ty/region.rs

@@ -82,8 +82,8 @@ impl<'tcx> Region<'tcx> {
         tcx.intern_region(ty::ReError(reported))
     }
 
-    /// Constructs a `RegionKind::ReError` region and registers a `span_delayed_bug` to ensure it
+    /// Constructs a `RegionKind::ReError` region and registers a delayed bug to ensure it gets
-    /// gets used.
+    /// used.
     #[track_caller]
     pub fn new_error_misc(tcx: TyCtxt<'tcx>) -> Region<'tcx> {
         Region::new_error_with_message(
@@ -93,8 +93,8 @@ impl<'tcx> Region<'tcx> {
         )
     }
 
-    /// Constructs a `RegionKind::ReError` region and registers a `span_delayed_bug` with the given
+    /// Constructs a `RegionKind::ReError` region and registers a delayed bug with the given `msg`
-    /// `msg` to ensure it gets used.
+    /// to ensure it gets used.
     #[track_caller]
     pub fn new_error_with_message<S: Into<MultiSpan>>(
         tcx: TyCtxt<'tcx>,

compiler/rustc_middle/src/ty/visit.rs

@@ -55,7 +55,7 @@ pub trait TypeVisitableExt<'tcx>: TypeVisitable<TyCtxt<'tcx>> {
     }
     fn error_reported(&self) -> Result<(), ErrorGuaranteed> {
         if self.references_error() {
-            // We must include lint errors and span delayed bugs here.
+            // We must include lint errors and delayed bugs here.
             if let Some(reported) =
                 ty::tls::with(|tcx| tcx.dcx().has_errors_or_lint_errors_or_delayed_bugs())
             {

compiler/rustc_middle/src/util/bug.rs

@@ -38,16 +38,16 @@ fn opt_span_bug_fmt<S: Into<MultiSpan>>(
     })
 }
 
-/// A query to trigger a `span_delayed_bug`. Clearly, if one has a `tcx` one can already trigger a
+/// A query to trigger a delayed bug. Clearly, if one has a `tcx` one can already trigger a
-/// `span_delayed_bug`, so what is the point of this? It exists to help us test `span_delayed_bug`'s
+/// delayed bug, so what is the point of this? It exists to help us test the interaction of delayed
-/// interactions with the query system and incremental.
+/// bugs with the query system and incremental.
-pub fn trigger_span_delayed_bug(tcx: TyCtxt<'_>, key: rustc_hir::def_id::DefId) {
+pub fn trigger_delayed_bug(tcx: TyCtxt<'_>, key: rustc_hir::def_id::DefId) {
     tcx.dcx().span_delayed_bug(
         tcx.def_span(key),
-        "delayed span bug triggered by #[rustc_error(span_delayed_bug_from_inside_query)]",
+        "delayed bug triggered by #[rustc_error(delayed_bug_from_inside_query)]",
     );
 }
 
 pub fn provide(providers: &mut crate::query::Providers) {
-    *providers = crate::query::Providers { trigger_span_delayed_bug, ..*providers };
+    *providers = crate::query::Providers { trigger_delayed_bug, ..*providers };
 }

compiler/rustc_mir_transform/src/coroutine.rs

@@ -726,7 +726,7 @@ fn replace_resume_ty_local<'tcx>(
 /// The async lowering step and the type / lifetime inference / checking are
 /// still using the `resume` argument for the time being. After this transform,
 /// the coroutine body doesn't have the `resume` argument.
-fn transform_gen_context<'tcx>(_tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+fn transform_gen_context<'tcx>(body: &mut Body<'tcx>) {
     // This leaves the local representing the `resume` argument in place,
     // but turns it into a regular local variable. This is cheaper than
     // adjusting all local references in the body after removing it.
@@ -1733,7 +1733,7 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
 
         // Remove the context argument within generator bodies.
         if matches!(coroutine_kind, CoroutineKind::Desugared(CoroutineDesugaring::Gen, _)) {
-            transform_gen_context(tcx, body);
+            transform_gen_context(body);
         }
 
         // The original arguments to the function are no longer arguments, mark them as such.

compiler/rustc_mir_transform/src/inline.rs

@@ -2,6 +2,7 @@
 use crate::deref_separator::deref_finder;
 use rustc_attr::InlineAttr;
 use rustc_const_eval::transform::validate::validate_types;
+use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
 use rustc_index::bit_set::BitSet;
 use rustc_index::Idx;
@@ -384,6 +385,17 @@ impl<'tcx> Inliner<'tcx> {
                 }
 
                 let fn_sig = self.tcx.fn_sig(def_id).instantiate(self.tcx, args);
+
+                // Additionally, check that the body that we're inlining actually agrees
+                // with the ABI of the trait that the item comes from.
+                if let InstanceDef::Item(instance_def_id) = callee.def
+                    && self.tcx.def_kind(instance_def_id) == DefKind::AssocFn
+                    && let instance_fn_sig = self.tcx.fn_sig(instance_def_id).skip_binder()
+                    && instance_fn_sig.abi() != fn_sig.abi()
+                {
+                    return None;
+                }
+
                 let source_info = SourceInfo { span: fn_span, ..terminator.source_info };
 
                 return Some(CallSite { callee, fn_sig, block: bb, source_info });

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -29,17 +29,14 @@ impl<'tcx> MirPass<'tcx> for InstSimplify {
                         ctx.simplify_bool_cmp(&statement.source_info, rvalue);
                         ctx.simplify_ref_deref(&statement.source_info, rvalue);
                         ctx.simplify_len(&statement.source_info, rvalue);
-                        ctx.simplify_cast(&statement.source_info, rvalue);
+                        ctx.simplify_cast(rvalue);
                     }
                     _ => {}
                 }
             }
 
             ctx.simplify_primitive_clone(block.terminator.as_mut().unwrap(), &mut block.statements);
-            ctx.simplify_intrinsic_assert(
+            ctx.simplify_intrinsic_assert(block.terminator.as_mut().unwrap());
-                block.terminator.as_mut().unwrap(),
-                &mut block.statements,
-            );
             ctx.simplify_nounwind_call(block.terminator.as_mut().unwrap());
             simplify_duplicate_switch_targets(block.terminator.as_mut().unwrap());
         }
@@ -143,7 +140,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
         }
     }
 
-    fn simplify_cast(&self, _source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+    fn simplify_cast(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Cast(kind, operand, cast_ty) = rvalue {
             let operand_ty = operand.ty(self.local_decls, self.tcx);
             if operand_ty == *cast_ty {
@@ -277,11 +274,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
         }
     }
 
-    fn simplify_intrinsic_assert(
+    fn simplify_intrinsic_assert(&self, terminator: &mut Terminator<'tcx>) {
-        &self,
-        terminator: &mut Terminator<'tcx>,
-        _statements: &mut Vec<Statement<'tcx>>,
-    ) {
         let TerminatorKind::Call { func, target, .. } = &mut terminator.kind else {
             return;
         };

compiler/rustc_passes/src/check_attr.rs

@@ -197,7 +197,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 | sym::unstable
                 | sym::stable
                 | sym::rustc_allowed_through_unstable_modules
-                | sym::rustc_promotable => self.check_stability_promotable(attr, span, target),
+                | sym::rustc_promotable => self.check_stability_promotable(attr, target),
                 sym::link_ordinal => self.check_link_ordinal(attr, span, target),
                 sym::rustc_confusables => self.check_confusables(attr, target),
                 sym::rustc_safe_intrinsic => {
@@ -2099,7 +2099,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    fn check_stability_promotable(&self, attr: &Attribute, _span: Span, target: Target) -> bool {
+    fn check_stability_promotable(&self, attr: &Attribute, target: Target) -> bool {
         match target {
             Target::Expression => {
                 self.dcx().emit_err(errors::StabilityPromotable { attr_span: attr.span });

compiler/rustc_span/src/symbol.rs

@@ -656,6 +656,7 @@ symbols! {
         default_method_body_is_const,
         default_type_parameter_fallback,
         default_type_params,
+        delayed_bug_from_inside_query,
         deny,
         deprecated,
         deprecated_safe,
@@ -1580,7 +1581,6 @@ symbols! {
         slice_patterns,
         slicing_syntax,
         soft,
-        span_delayed_bug_from_inside_query,
         specialization,
         speed,
         spotlight,

compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs

@@ -261,12 +261,7 @@ fn encode_predicates<'tcx>(
 }
 
 /// Encodes a region using the Itanium C++ ABI as a vendor extended type.
-fn encode_region<'tcx>(
+fn encode_region<'tcx>(region: Region<'tcx>, dict: &mut FxHashMap<DictKey<'tcx>, usize>) -> String {
-    _tcx: TyCtxt<'tcx>,
-    region: Region<'tcx>,
-    dict: &mut FxHashMap<DictKey<'tcx>, usize>,
-    _options: EncodeTyOptions,
-) -> String {
     // u6region[I[<region-disambiguator>][<region-index>]E] as vendor extended type
     let mut s = String::new();
     match region.kind() {
@@ -314,7 +309,7 @@ fn encode_args<'tcx>(
         for arg in args {
             match arg.unpack() {
                 GenericArgKind::Lifetime(region) => {
-                    s.push_str(&encode_region(tcx, region, dict, options));
+                    s.push_str(&encode_region(region, dict));
                 }
                 GenericArgKind::Type(ty) => {
                     s.push_str(&encode_ty(tcx, ty, dict, options));
@@ -704,7 +699,7 @@ fn encode_ty<'tcx>(
                 ty::DynStar => "u7dynstarI",
             });
             s.push_str(&encode_predicates(tcx, predicates, dict, options));
-            s.push_str(&encode_region(tcx, *region, dict, options));
+            s.push_str(&encode_region(*region, dict));
             s.push('E');
             compress(dict, DictKey::Ty(ty, TyQ::None), &mut s);
             typeid.push_str(&s);
@@ -736,7 +731,6 @@ fn encode_ty<'tcx>(
 fn transform_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: &List<ty::PolyExistentialPredicate<'tcx>>,
-    _options: EncodeTyOptions,
 ) -> &'tcx List<ty::PolyExistentialPredicate<'tcx>> {
     let predicates: Vec<ty::PolyExistentialPredicate<'tcx>> = predicates
         .iter()
@@ -968,7 +962,7 @@ fn transform_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, options: TransformTyOptio
         ty::Dynamic(predicates, _region, kind) => {
             ty = Ty::new_dynamic(
                 tcx,
-                transform_predicates(tcx, predicates, options),
+                transform_predicates(tcx, predicates),
                 tcx.lifetimes.re_erased,
                 *kind,
             );

compiler/rustc_trait_selection/src/solve/assembly/mod.rs

@@ -15,7 +15,7 @@ use rustc_middle::ty::fast_reject::{SimplifiedType, TreatParams};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::ty::{fast_reject, TypeFoldable};
 use rustc_middle::ty::{ToPredicate, TypeVisitableExt};
-use rustc_span::ErrorGuaranteed;
+use rustc_span::{ErrorGuaranteed, DUMMY_SP};
 use std::fmt::Debug;
 
 pub(super) mod structural_traits;
@@ -612,7 +612,11 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
 
             ty::Alias(kind @ (ty::Projection | ty::Opaque), alias_ty) => (kind, alias_ty),
             ty::Alias(ty::Inherent | ty::Weak, _) => {
-                unreachable!("Weak and Inherent aliases should have been normalized away already")
+                self.tcx().sess.dcx().span_delayed_bug(
+                    DUMMY_SP,
+                    format!("could not normalize {self_ty}, it is not WF"),
+                );
+                return;
             }
         };
 

compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs

@@ -615,8 +615,6 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
                         let UnsatisfiedConst(unsatisfied_const) = self
                             .maybe_add_note_for_unsatisfied_const(
-                                &obligation,
-                                trait_ref,
                                 &trait_predicate,
                                 &mut err,
                                 span,
@@ -1480,8 +1478,6 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
 
     fn maybe_add_note_for_unsatisfied_const(
         &self,
-        obligation: &PredicateObligation<'tcx>,
-        trait_ref: ty::PolyTraitRef<'tcx>,
         trait_predicate: &ty::PolyTraitPredicate<'tcx>,
         err: &mut Diagnostic,
         span: Span,
@@ -3359,8 +3355,6 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
     fn maybe_add_note_for_unsatisfied_const(
         &self,
-        _obligation: &PredicateObligation<'tcx>,
-        _trait_ref: ty::PolyTraitRef<'tcx>,
         _trait_predicate: &ty::PolyTraitPredicate<'tcx>,
         _err: &mut Diagnostic,
         _span: Span,

library/alloc/src/collections/btree/map.rs

@@ -2522,10 +2522,17 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         self.len() == 0
     }
 
-    /// Returns a [`Cursor`] pointing to the first gap above the given bound.
+    /// Returns a [`Cursor`] pointing at the gap before the smallest key
+    /// greater than the given bound.
     ///
-    /// Passing [`Bound::Unbounded`] will return a cursor pointing to the start
+    /// Passing `Bound::Included(x)` will return a cursor pointing to the
-    /// of the map.
+    /// gap before the smallest key greater than or equal to `x`.
+    ///
+    /// Passing `Bound::Excluded(x)` will return a cursor pointing to the
+    /// gap before the smallest key greater than `x`.
+    ///
+    /// Passing `Bound::Unbounded` will return a cursor pointing to the
+    /// gap before the smallest key in the map.
     ///
     /// # Examples
     ///
@@ -2535,17 +2542,24 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// use std::collections::BTreeMap;
     /// use std::ops::Bound;
     ///
-    /// let mut a = BTreeMap::new();
+    /// let map = BTreeMap::from([
-    /// a.insert(1, "a");
+    ///     (1, "a"),
-    /// a.insert(2, "b");
+    ///     (2, "b"),
-    /// a.insert(3, "c");
+    ///     (3, "c"),
-    /// a.insert(4, "d");
+    ///     (4, "d"),
-    /// let cursor = a.lower_bound(Bound::Included(&2));
+    /// ]);
+    ///
+    /// let cursor = map.lower_bound(Bound::Included(&2));
     /// assert_eq!(cursor.peek_prev(), Some((&1, &"a")));
     /// assert_eq!(cursor.peek_next(), Some((&2, &"b")));
-    /// let cursor = a.lower_bound(Bound::Excluded(&2));
+    ///
+    /// let cursor = map.lower_bound(Bound::Excluded(&2));
     /// assert_eq!(cursor.peek_prev(), Some((&2, &"b")));
     /// assert_eq!(cursor.peek_next(), Some((&3, &"c")));
+    ///
+    /// let cursor = map.lower_bound(Bound::Unbounded);
+    /// assert_eq!(cursor.peek_prev(), None);
+    /// assert_eq!(cursor.peek_next(), Some((&1, &"a")));
     /// ```
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn lower_bound<Q: ?Sized>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
@@ -2561,11 +2575,17 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         Cursor { current: Some(edge), root: self.root.as_ref() }
     }
 
-    /// Returns a [`CursorMut`] pointing to the first gap above the given bound.
+    /// Returns a [`CursorMut`] pointing at the gap before the smallest key
+    /// greater than the given bound.
     ///
+    /// Passing `Bound::Included(x)` will return a cursor pointing to the
+    /// gap before the smallest key greater than or equal to `x`.
     ///
-    /// Passing [`Bound::Unbounded`] will return a cursor pointing to the start
+    /// Passing `Bound::Excluded(x)` will return a cursor pointing to the
-    /// of the map.
+    /// gap before the smallest key greater than `x`.
+    ///
+    /// Passing `Bound::Unbounded` will return a cursor pointing to the
+    /// gap before the smallest key in the map.
     ///
     /// # Examples
     ///
@@ -2575,17 +2595,24 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// use std::collections::BTreeMap;
     /// use std::ops::Bound;
     ///
-    /// let mut a = BTreeMap::new();
+    /// let mut map = BTreeMap::from([
-    /// a.insert(1, "a");
+    ///     (1, "a"),
-    /// a.insert(2, "b");
+    ///     (2, "b"),
-    /// a.insert(3, "c");
+    ///     (3, "c"),
-    /// a.insert(4, "d");
+    ///     (4, "d"),
-    /// let mut cursor = a.lower_bound_mut(Bound::Included(&2));
+    /// ]);
+    ///
+    /// let mut cursor = map.lower_bound_mut(Bound::Included(&2));
     /// assert_eq!(cursor.peek_prev(), Some((&1, &mut "a")));
     /// assert_eq!(cursor.peek_next(), Some((&2, &mut "b")));
-    /// let mut cursor = a.lower_bound_mut(Bound::Excluded(&2));
+    ///
+    /// let mut cursor = map.lower_bound_mut(Bound::Excluded(&2));
     /// assert_eq!(cursor.peek_prev(), Some((&2, &mut "b")));
     /// assert_eq!(cursor.peek_next(), Some((&3, &mut "c")));
+    ///
+    /// let mut cursor = map.lower_bound_mut(Bound::Unbounded);
+    /// assert_eq!(cursor.peek_prev(), None);
+    /// assert_eq!(cursor.peek_next(), Some((&1, &mut "a")));
     /// ```
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn lower_bound_mut<Q: ?Sized>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
@@ -2618,10 +2645,17 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         }
     }
 
-    /// Returns a [`Cursor`] pointing at the last gap below the given bound.
+    /// Returns a [`Cursor`] pointing at the gap after the greatest key
+    /// smaller than the given bound.
     ///
-    /// Passing [`Bound::Unbounded`] will return a cursor pointing to the end
+    /// Passing `Bound::Included(x)` will return a cursor pointing to the
-    /// of the map.
+    /// gap after the greatest key smaller than or equal to `x`.
+    ///
+    /// Passing `Bound::Excluded(x)` will return a cursor pointing to the
+    /// gap after the greatest key smaller than `x`.
+    ///
+    /// Passing `Bound::Unbounded` will return a cursor pointing to the
+    /// gap after the greatest key in the map.
     ///
     /// # Examples
     ///
@@ -2631,17 +2665,24 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// use std::collections::BTreeMap;
     /// use std::ops::Bound;
     ///
-    /// let mut a = BTreeMap::new();
+    /// let map = BTreeMap::from([
-    /// a.insert(1, "a");
+    ///     (1, "a"),
-    /// a.insert(2, "b");
+    ///     (2, "b"),
-    /// a.insert(3, "c");
+    ///     (3, "c"),
-    /// a.insert(4, "d");
+    ///     (4, "d"),
-    /// let cursor = a.upper_bound(Bound::Included(&3));
+    /// ]);
+    ///
+    /// let cursor = map.upper_bound(Bound::Included(&3));
     /// assert_eq!(cursor.peek_prev(), Some((&3, &"c")));
     /// assert_eq!(cursor.peek_next(), Some((&4, &"d")));
-    /// let cursor = a.upper_bound(Bound::Excluded(&3));
+    ///
+    /// let cursor = map.upper_bound(Bound::Excluded(&3));
     /// assert_eq!(cursor.peek_prev(), Some((&2, &"b")));
     /// assert_eq!(cursor.peek_next(), Some((&3, &"c")));
+    ///
+    /// let cursor = map.upper_bound(Bound::Unbounded);
+    /// assert_eq!(cursor.peek_prev(), Some((&4, &"d")));
+    /// assert_eq!(cursor.peek_next(), None);
     /// ```
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn upper_bound<Q: ?Sized>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
@@ -2657,10 +2698,17 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         Cursor { current: Some(edge), root: self.root.as_ref() }
     }
 
-    /// Returns a [`CursorMut`] pointing at the last gap below the given bound.
+    /// Returns a [`CursorMut`] pointing at the gap after the greatest key
+    /// smaller than the given bound.
     ///
-    /// Passing [`Bound::Unbounded`] will return a cursor pointing to the end
+    /// Passing `Bound::Included(x)` will return a cursor pointing to the
-    /// of the map.
+    /// gap after the greatest key smaller than or equal to `x`.
+    ///
+    /// Passing `Bound::Excluded(x)` will return a cursor pointing to the
+    /// gap after the greatest key smaller than `x`.
+    ///
+    /// Passing `Bound::Unbounded` will return a cursor pointing to the
+    /// gap after the greatest key in the map.
     ///
     /// # Examples
     ///
@@ -2670,17 +2718,24 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// use std::collections::BTreeMap;
     /// use std::ops::Bound;
     ///
-    /// let mut a = BTreeMap::new();
+    /// let mut map = BTreeMap::from([
-    /// a.insert(1, "a");
+    ///     (1, "a"),
-    /// a.insert(2, "b");
+    ///     (2, "b"),
-    /// a.insert(3, "c");
+    ///     (3, "c"),
-    /// a.insert(4, "d");
+    ///     (4, "d"),
-    /// let mut cursor = a.upper_bound_mut(Bound::Included(&3));
+    /// ]);
+    ///
+    /// let mut cursor = map.upper_bound_mut(Bound::Included(&3));
     /// assert_eq!(cursor.peek_prev(), Some((&3, &mut "c")));
     /// assert_eq!(cursor.peek_next(), Some((&4, &mut "d")));
-    /// let mut cursor = a.upper_bound_mut(Bound::Excluded(&3));
+    ///
+    /// let mut cursor = map.upper_bound_mut(Bound::Excluded(&3));
     /// assert_eq!(cursor.peek_prev(), Some((&2, &mut "b")));
     /// assert_eq!(cursor.peek_next(), Some((&3, &mut "c")));
+    ///
+    /// let mut cursor = map.upper_bound_mut(Bound::Unbounded);
+    /// assert_eq!(cursor.peek_prev(), Some((&4, &mut "d")));
+    /// assert_eq!(cursor.peek_next(), None);
     /// ```
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn upper_bound_mut<Q: ?Sized>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
@@ -3040,8 +3095,8 @@ impl<'a, K, V, A> CursorMutKey<'a, K, V, A> {
 
 // Now the tree editing operations
 impl<'a, K: Ord, V, A: Allocator + Clone> CursorMutKey<'a, K, V, A> {
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMutKey` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap before the
     /// newly inserted element.
@@ -3083,8 +3138,8 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMutKey<'a, K, V, A> {
         *self.length += 1;
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMutKey` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap after the
     /// newly inserted element.
@@ -3129,19 +3184,16 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMutKey<'a, K, V, A> {
         *self.length += 1;
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMutKey` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap before the
     /// newly inserted element.
     ///
-    /// # Panics
+    /// If the inserted key is not greater than the key before the cursor
-    ///
+    /// (if any), or if it not less than the key after the cursor (if any),
-    /// This function panics if:
+    /// then an [`UnorderedKeyError`] is returned since this would
-    /// - the given key compares less than or equal to the current element (if
+    /// invalidate the [`Ord`] invariant between the keys of the map.
-    ///   any).
-    /// - the given key compares greater than or equal to the next element (if
-    ///   any).
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn insert_after(&mut self, key: K, value: V) -> Result<(), UnorderedKeyError> {
         if let Some((prev, _)) = self.peek_prev() {
@@ -3160,19 +3212,16 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMutKey<'a, K, V, A> {
         Ok(())
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMutKey` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap after the
     /// newly inserted element.
     ///
-    /// # Panics
+    /// If the inserted key is not greater than the key before the cursor
-    ///
+    /// (if any), or if it not less than the key after the cursor (if any),
-    /// This function panics if:
+    /// then an [`UnorderedKeyError`] is returned since this would
-    /// - the given key compares greater than or equal to the current element
+    /// invalidate the [`Ord`] invariant between the keys of the map.
-    ///   (if any).
-    /// - the given key compares less than or equal to the previous element (if
-    ///   any).
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn insert_before(&mut self, key: K, value: V) -> Result<(), UnorderedKeyError> {
         if let Some((prev, _)) = self.peek_prev() {
@@ -3239,10 +3288,10 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMutKey<'a, K, V, A> {
 }
 
 impl<'a, K: Ord, V, A: Allocator + Clone> CursorMut<'a, K, V, A> {
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMut` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
-    /// After the insertion the cursor will be pointing at the gap before the
+    /// After the insertion the cursor will be pointing at the gap after the
     /// newly inserted element.
     ///
     /// # Safety
@@ -3257,8 +3306,8 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMut<'a, K, V, A> {
         unsafe { self.inner.insert_after_unchecked(key, value) }
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMut` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap after the
     /// newly inserted element.
@@ -3275,37 +3324,31 @@ impl<'a, K: Ord, V, A: Allocator + Clone> CursorMut<'a, K, V, A> {
         unsafe { self.inner.insert_before_unchecked(key, value) }
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMut` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap before the
     /// newly inserted element.
     ///
-    /// # Panics
+    /// If the inserted key is not greater than the key before the cursor
-    ///
+    /// (if any), or if it not less than the key after the cursor (if any),
-    /// This function panics if:
+    /// then an [`UnorderedKeyError`] is returned since this would
-    /// - the given key compares less than or equal to the current element (if
+    /// invalidate the [`Ord`] invariant between the keys of the map.
-    ///   any).
-    /// - the given key compares greater than or equal to the next element (if
-    ///   any).
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn insert_after(&mut self, key: K, value: V) -> Result<(), UnorderedKeyError> {
         self.inner.insert_after(key, value)
     }
 
-    /// Inserts a new element into the `BTreeMap` in the gap that the
+    /// Inserts a new key-value pair into the map in the gap that the
-    /// `CursorMut` is currently pointing to.
+    /// cursor is currently pointing to.
     ///
     /// After the insertion the cursor will be pointing at the gap after the
     /// newly inserted element.
     ///
-    /// # Panics
+    /// If the inserted key is not greater than the key before the cursor
-    ///
+    /// (if any), or if it not less than the key after the cursor (if any),
-    /// This function panics if:
+    /// then an [`UnorderedKeyError`] is returned since this would
-    /// - the given key compares greater than or equal to the current element
+    /// invalidate the [`Ord`] invariant between the keys of the map.
-    ///   (if any).
-    /// - the given key compares less than or equal to the previous element (if
-    ///   any).
     #[unstable(feature = "btree_cursors", issue = "107540")]
     pub fn insert_before(&mut self, key: K, value: V) -> Result<(), UnorderedKeyError> {
         self.inner.insert_before(key, value)

src/librustdoc/clean/mod.rs

@@ -1840,7 +1840,9 @@ fn maybe_expand_private_type_alias<'tcx>(
         }
     }
 
-    Some(cx.enter_alias(args, def_id.to_def_id(), |cx| clean_ty(&ty, cx)))
+    Some(cx.enter_alias(args, def_id.to_def_id(), |cx| {
+        cx.with_param_env(def_id.to_def_id(), |cx| clean_ty(&ty, cx))
+    }))
 }
 
 pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type {

src/tools/clippy/tests/integration.rs

@@ -77,7 +77,7 @@ fn integration_test() {
         // the repo basically just contains a span_delayed_bug that forces rustc/clippy to panic:
         /*
            #![feature(rustc_attrs)]
-           #[rustc_error(span_delayed_bug_from_inside_query)]
+           #[rustc_error(delayed_bug_from_inside_query)]
            fn main() {}
         */
 

src/tools/rust-analyzer/crates/hir-def/src/attr/builtin.rs

@@ -650,7 +650,7 @@ pub const INERT_ATTRIBUTES: &[BuiltinAttribute] = &[
     rustc_attr!(TEST, rustc_regions, Normal, template!(Word), WarnFollowing),
     rustc_attr!(
         TEST, rustc_error, Normal,
-        template!(Word, List: "span_delayed_bug_from_inside_query"), WarnFollowingWordOnly
+        template!(Word, List: "delayed_bug_from_inside_query"), WarnFollowingWordOnly
     ),
     rustc_attr!(TEST, rustc_dump_user_args, Normal, template!(Word), WarnFollowing),
     rustc_attr!(TEST, rustc_evaluate_where_clauses, Normal, template!(Word), WarnFollowing),

tests/incremental/delayed_span_bug.rs

@@ -1,8 +1,8 @@
 // revisions: cfail1 cfail2
 // should-ice
-// error-pattern: delayed span bug triggered by #[rustc_error(span_delayed_bug_from_inside_query)]
+// error-pattern: delayed bug triggered by #[rustc_error(delayed_bug_from_inside_query)]
 
 #![feature(rustc_attrs)]
 
-#[rustc_error(span_delayed_bug_from_inside_query)]
+#[rustc_error(delayed_bug_from_inside_query)]
 fn main() {}

tests/rustdoc-ui/normalize-in-inlined-type-alias.rs

@@ -0,0 +1,14 @@
+// check-pass
+// compile-flags: -Znormalize-docs
+
+trait Woo<T> {
+    type Assoc;
+}
+
+impl<T> Woo<T> for () {
+    type Assoc = ();
+}
+
+type Alias<P> = <() as Woo<P>>::Assoc;
+
+pub fn hello<S>() -> Alias<S> {}

tests/ui/coercion/type-errors.rs

@@ -1,15 +1,26 @@
-// Regression test for an ICE: https://github.com/rust-lang/rust/issues/120884
+// Test that we don't ICE for coercions with type errors.
 // We still need to properly go through coercions between types with errors instead of
 // shortcutting and returning success, because we need the adjustments for building the MIR.
 
 pub fn has_error() -> TypeError {}
 //~^ ERROR cannot find type `TypeError` in this scope
 
+// https://github.com/rust-lang/rust/issues/120884
+// Casting a function item to a data pointer in valid in HIR, but invalid in MIR.
+// We need an adjustment (ReifyFnPointer) to insert a cast from the function item
+// to a function pointer as a separate MIR statement.
 pub fn cast() -> *const u8 {
-    // Casting a function item to a data pointer in valid in HIR, but invalid in MIR.
-    // We need an adjustment (ReifyFnPointer) to insert a cast from the function item
-    // to a function pointer as a separate MIR statement.
     has_error as *const u8
 }
 
+// https://github.com/rust-lang/rust/issues/120945
+// This one ICEd, because we skipped the builtin deref from `&TypeError` to `TypeError`.
+pub fn autoderef_source(e: &TypeError) {
+    //~^ ERROR cannot find type `TypeError` in this scope
+    autoderef_target(e)
+}
+
+pub fn autoderef_target(_: &TypeError) {}
+//~^ ERROR cannot find type `TypeError` in this scope
+
 fn main() {}

tests/ui/coercion/type-errors.stderr

@@ -4,6 +4,18 @@ error[E0412]: cannot find type `TypeError` in this scope
 LL | pub fn has_error() -> TypeError {}
    |                       ^^^^^^^^^ not found in this scope
 
-error: aborting due to 1 previous error
+error[E0412]: cannot find type `TypeError` in this scope
+  --> $DIR/type-errors.rs:18:29
+   |
+LL | pub fn autoderef_source(e: &TypeError) {
+   |                             ^^^^^^^^^ not found in this scope
+
+error[E0412]: cannot find type `TypeError` in this scope
+  --> $DIR/type-errors.rs:23:29
+   |
+LL | pub fn autoderef_target(_: &TypeError) {}
+   |                             ^^^^^^^^^ not found in this scope
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0412`.

tests/ui/consts/issue-17718-const-bad-values.rs

@@ -4,7 +4,6 @@ const C1: &'static mut [usize] = &mut [];
 static mut S: usize = 3;
 const C2: &'static mut usize = unsafe { &mut S };
 //~^ ERROR: referencing statics in constants
-//~| ERROR: referencing statics in constants
 //~| WARN mutable reference of mutable static is discouraged [static_mut_ref]
 
 fn main() {}

tests/ui/consts/issue-17718-const-bad-values.stderr

@@ -31,20 +31,7 @@ LL | const C2: &'static mut usize = unsafe { &mut S };
    = note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
    = help: to fix this, the value can be extracted to a `const` and then used.
 
-error[E0658]: referencing statics in constants is unstable
+error: aborting due to 2 previous errors; 1 warning emitted
-  --> $DIR/issue-17718-const-bad-values.rs:5:46
-   |
-LL | const C2: &'static mut usize = unsafe { &mut S };
-   |                                              ^
-   |
-   = note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
-   = help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
-   = help: to fix this, the value can be extracted to a `const` and then used.
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 3 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0658, E0764.
 For more information about an error, try `rustc --explain E0658`.

tests/ui/consts/miri_unleashed/const_refers_to_static.32bit.stderr

@@ -49,11 +49,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const READ_MUT: u32 = unsafe { MUTABLE };
    |                                ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static.rs:18:32
-   |
-LL | const READ_MUT: u32 = unsafe { MUTABLE };
-   |                                ^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/const_refers_to_static.rs:24:18
    |

tests/ui/consts/miri_unleashed/const_refers_to_static.64bit.stderr

@@ -49,11 +49,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const READ_MUT: u32 = unsafe { MUTABLE };
    |                                ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static.rs:18:32
-   |
-LL | const READ_MUT: u32 = unsafe { MUTABLE };
-   |                                ^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/const_refers_to_static.rs:24:18
    |

tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.32bit.stderr

@@ -83,21 +83,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL |     unsafe { &static_cross_crate::ZERO }
    |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:12:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:18:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO[0] }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:18:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO[0] }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/const_refers_to_static_cross_crate.rs:18:15
    |
@@ -113,26 +98,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL |         match static_cross_crate::OPT_ZERO {
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 8 previous errors; 2 warnings emitted
 

tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.64bit.stderr

@@ -83,21 +83,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL |     unsafe { &static_cross_crate::ZERO }
    |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:12:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:18:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO[0] }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:18:15
-   |
-LL |     unsafe { &static_cross_crate::ZERO[0] }
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/const_refers_to_static_cross_crate.rs:18:15
    |
@@ -113,26 +98,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL |         match static_cross_crate::OPT_ZERO {
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/const_refers_to_static_cross_crate.rs:28:15
-   |
-LL |         match static_cross_crate::OPT_ZERO {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 8 previous errors; 2 warnings emitted
 

tests/ui/consts/miri_unleashed/mutable_references_err.32bit.stderr

@@ -114,11 +114,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
    |                                        ^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:32:40
-   |
-LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
-   |                                        ^^^
 help: skipping check that does not even have a feature gate
   --> $DIR/mutable_references_err.rs:32:35
    |
@@ -144,16 +139,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
    |                                            ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:47:44
-   |
-LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
-   |                                            ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:51:45
-   |
-LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
-   |                                             ^^^^^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/mutable_references_err.rs:51:45
    |

tests/ui/consts/miri_unleashed/mutable_references_err.64bit.stderr

@@ -114,11 +114,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
    |                                        ^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:32:40
-   |
-LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
-   |                                        ^^^
 help: skipping check that does not even have a feature gate
   --> $DIR/mutable_references_err.rs:32:35
    |
@@ -144,16 +139,6 @@ help: skipping check for `const_refs_to_static` feature
    |
 LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
    |                                            ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:47:44
-   |
-LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
-   |                                            ^^^^^^^
-help: skipping check for `const_refs_to_static` feature
-  --> $DIR/mutable_references_err.rs:51:45
-   |
-LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
-   |                                             ^^^^^^^^^^^
 help: skipping check for `const_refs_to_static` feature
   --> $DIR/mutable_references_err.rs:51:45
    |

tests/ui/feature-gates/feature-gate-const-refs-to-static.rs

@@ -6,7 +6,6 @@ const C1_READ: () = {
     assert!(*C1 == 0);
 };
 const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) }; //~ERROR:  referencing statics in constants is unstable
-//~^ERROR:  referencing statics in constants is unstable
 
 fn main() {
 }

tests/ui/feature-gates/feature-gate-const-refs-to-static.stderr

@@ -22,19 +22,6 @@ LL | const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
    = note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
    = help: to fix this, the value can be extracted to a `const` and then used.
 
-error[E0658]: referencing statics in constants is unstable
+error: aborting due to 2 previous errors
-  --> $DIR/feature-gate-const-refs-to-static.rs:8:52
-   |
-LL | const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
-   |                                                    ^^^^^
-   |
-   = note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
-   = help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
-   = help: to fix this, the value can be extracted to a `const` and then used.
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0658`.

tests/ui/impl-trait/in-trait/alias-bounds-when-not-wf.rs

@@ -0,0 +1,19 @@
+// compile-flags: -Znext-solver
+
+#![feature(lazy_type_alias)]
+//~^ WARN the feature `lazy_type_alias` is incomplete
+
+trait Foo {}
+
+type A<T: Foo> = T;
+
+struct W<T>(T);
+
+// For `W<A<usize>>` to be WF, `A<usize>: Sized` must hold. However, when assembling
+// alias bounds for `A<usize>`, we try to normalize it, but it doesn't hold because
+// `usize: Foo` doesn't hold. Therefore we ICE, because we don't expect to still
+// encounter weak types in `assemble_alias_bound_candidates_recur`.
+fn hello(_: W<A<usize>>) {}
+//~^ ERROR the type `W<A<usize>>` is not well-formed
+
+fn main() {}

tests/ui/impl-trait/in-trait/alias-bounds-when-not-wf.stderr

@@ -0,0 +1,17 @@
+warning: the feature `lazy_type_alias` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/alias-bounds-when-not-wf.rs:3:12
+   |
+LL | #![feature(lazy_type_alias)]
+   |            ^^^^^^^^^^^^^^^
+   |
+   = note: see issue #112792 <https://github.com/rust-lang/rust/issues/112792> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: the type `W<A<usize>>` is not well-formed
+  --> $DIR/alias-bounds-when-not-wf.rs:16:13
+   |
+LL | fn hello(_: W<A<usize>>) {}
+   |             ^^^^^^^^^^^
+
+error: aborting due to 1 previous error; 1 warning emitted
+

tests/ui/mir/inline-wrong-abi.rs

@@ -0,0 +1,32 @@
+// compile-flags: -Zpolymorphize=on -Zinline-mir=yes -Zmir-opt-level=0
+
+#![feature(fn_traits, unboxed_closures)]
+struct Foo<T>(T);
+
+impl<T: Copy> Fn<()> for Foo<T> {
+    extern "C" fn call(&self, _: ()) -> T {
+        //~^ ERROR method `call` has an incompatible type for trait
+        match *self {
+            Foo(t) => t,
+        }
+    }
+}
+
+impl<T: Copy> FnMut<()> for Foo<T> {
+    extern "rust-call" fn call_mut(&mut self, _: ()) -> T {
+        self.call(())
+    }
+}
+
+impl<T: Copy> FnOnce<()> for Foo<T> {
+    type Output = T;
+
+    extern "rust-call" fn call_once(self, _: ()) -> T {
+        self.call(())
+    }
+}
+
+fn main() {
+    let t: u8 = 1;
+    println!("{}", Foo(t)());
+}

tests/ui/mir/inline-wrong-abi.stderr

@@ -0,0 +1,12 @@
+error[E0053]: method `call` has an incompatible type for trait
+  --> $DIR/inline-wrong-abi.rs:7:5
+   |
+LL |     extern "C" fn call(&self, _: ()) -> T {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected "rust-call" fn, found "C" fn
+   |
+   = note: expected signature `extern "rust-call" fn(&Foo<_>, ()) -> _`
+              found signature `extern "C" fn(&Foo<_>, ()) -> _`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0053`.

tests/ui/thread-local/thread-local-static.rs

@@ -12,7 +12,6 @@ const fn g(x: &mut [u32; 8]) {
     //~^^ ERROR thread-local statics cannot be accessed
     //~| ERROR mutable references are not allowed
     //~| ERROR use of mutable static is unsafe
-    //~| referencing statics
 }
 
 fn main() {}

tests/ui/thread-local/thread-local-static.stderr

@@ -37,18 +37,6 @@ error[E0625]: thread-local statics cannot be accessed at compile-time
 LL |     std::mem::swap(x, &mut STATIC_VAR_2)
    |                            ^^^^^^^^^^^^
 
-error[E0658]: referencing statics in constant functions is unstable
-  --> $DIR/thread-local-static.rs:10:28
-   |
-LL |     std::mem::swap(x, &mut STATIC_VAR_2)
-   |                            ^^^^^^^^^^^^
-   |
-   = note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
-   = help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
-   = help: to fix this, the value can be extracted to a `const` and then used.
-
 error[E0658]: mutable references are not allowed in constant functions
   --> $DIR/thread-local-static.rs:10:23
    |
@@ -59,7 +47,7 @@ LL |     std::mem::swap(x, &mut STATIC_VAR_2)
    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error: aborting due to 5 previous errors; 1 warning emitted
+error: aborting due to 4 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0133, E0625, E0658.
 For more information about an error, try `rustc --explain E0133`.

tests/ui/treat-err-as-bug/span_delayed_bug.rs

@@ -1,12 +1,12 @@
 // compile-flags: -Ztreat-err-as-bug -Zeagerly-emit-delayed-bugs
 // failure-status: 101
 // error-pattern: aborting due to `-Z treat-err-as-bug=1`
-// error-pattern: [trigger_span_delayed_bug] triggering a span delayed bug for testing incremental
+// error-pattern: [trigger_delayed_bug] triggering a delayed bug for testing incremental
 // normalize-stderr-test "note: .*\n\n" -> ""
 // normalize-stderr-test "thread 'rustc' panicked.*:\n.*\n" -> ""
 // rustc-env:RUST_BACKTRACE=0
 
 #![feature(rustc_attrs)]
 
-#[rustc_error(span_delayed_bug_from_inside_query)]
+#[rustc_error(delayed_bug_from_inside_query)]
 fn main() {}

tests/ui/treat-err-as-bug/span_delayed_bug.stderr

@@ -1,4 +1,4 @@
-error: internal compiler error: delayed span bug triggered by #[rustc_error(span_delayed_bug_from_inside_query)]
+error: internal compiler error: delayed bug triggered by #[rustc_error(delayed_bug_from_inside_query)]
   --> $DIR/span_delayed_bug.rs:12:1
    |
 LL | fn main() {}
@@ -7,5 +7,5 @@ LL | fn main() {}
 error: the compiler unexpectedly panicked. this is a bug.
 
 query stack during panic:
-#0 [trigger_span_delayed_bug] triggering a span delayed bug for testing incremental
+#0 [trigger_delayed_bug] triggering a delayed bug for testing incremental
 end of query stack

tests/ui/typeck/issue-116864.rs

@@ -0,0 +1,31 @@
+// compile-flags: -Znext-solver
+// check-pass
+// edition: 2021
+
+use std::future::Future;
+
+trait Baz {
+    type Param;
+}
+
+trait FnMutFut<P, R>: FnMut(P) -> Self::Future {
+    type Future: Future<Output = R>;
+}
+
+impl<P, F, FUT, R> FnMutFut<P, R> for F
+where
+    F: FnMut(P) -> FUT,
+    FUT: Future<Output = R>,
+{
+    type Future = FUT;
+}
+
+async fn foo<BAZ>(_: BAZ, mut cb: impl for<'any> FnMutFut<&'any BAZ::Param, ()>)
+where
+    BAZ: Baz<Param = i32>,
+{
+    cb(&1i32).await;
+}
+
+fn main() {
+}

triagebot.toml

@@ -810,7 +810,7 @@ project-stable-mir = [
 "/library/panic_abort" =                                 ["libs"]
 "/library/panic_unwind" =                                ["libs"]
 "/library/proc_macro" =                                  ["@petrochenkov"]
-"/library/std" =                                         ["libs"]
+"/library/std" =                                         ["libs", "@ChrisDenton"]
 "/library/std/src/sys/pal/windows" =                     ["@ChrisDenton"]
 "/library/stdarch" =                                     ["libs"]
 "/library/test" =                                        ["libs"]