Auto merge of #103220 - compiler-errors:deny-infers, r=lcnr

Deny hashing ty/re/ct inference variables

cc `@cjgillot` and https://github.com/rust-lang/rust/pull/102695#issuecomment-1275706528
r? `@lcnr`

best reviewed one commit at a time, mostly because the second commit that fixes `ClosureOutlivesRequirement` is mostly noise because of losing its `<'tcx>` lifetime parameter.

compiler/rustc_borrowck/src/constraints/mod.rs

@@ -92,7 +92,7 @@ pub struct OutlivesConstraint<'tcx> {
     pub span: Span,
 
     /// What caused this constraint?
-    pub category: ConstraintCategory<'tcx>,
+    pub category: ConstraintCategory,
 
     /// Variance diagnostic information
     pub variance_info: VarianceDiagInfo<'tcx>,

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -976,7 +976,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         err: &mut Diagnostic,
         location: Location,
         issued_borrow: &BorrowData<'tcx>,
-        explanation: BorrowExplanation<'tcx>,
+        explanation: BorrowExplanation,
     ) {
         let used_in_call = matches!(
             explanation,
@@ -1326,7 +1326,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         borrow: &BorrowData<'tcx>,
         drop_span: Span,
         borrow_spans: UseSpans<'tcx>,
-        explanation: BorrowExplanation<'tcx>,
+        explanation: BorrowExplanation,
     ) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
         debug!(
             "report_local_value_does_not_live_long_enough(\
@@ -1532,7 +1532,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         drop_span: Span,
         borrow_spans: UseSpans<'tcx>,
         proper_span: Span,
-        explanation: BorrowExplanation<'tcx>,
+        explanation: BorrowExplanation,
     ) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
         if let BorrowExplanation::MustBeValidFor { category, span, from_closure: false, .. } =
             explanation
@@ -1646,7 +1646,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         borrow: &BorrowData<'tcx>,
         borrow_span: Span,
         return_span: Span,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         opt_place_desc: Option<&String>,
     ) -> Option<DiagnosticBuilder<'cx, ErrorGuaranteed>> {
         let return_kind = match category {
@@ -1741,7 +1741,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         use_span: UseSpans<'tcx>,
         var_span: Span,
         fr_name: &RegionName,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         constraint_span: Span,
         captured_var: &str,
     ) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -21,7 +21,7 @@ use crate::{
 use super::{find_use, RegionName, UseSpans};
 
 #[derive(Debug)]
-pub(crate) enum BorrowExplanation<'tcx> {
+pub(crate) enum BorrowExplanation {
     UsedLater(LaterUseKind, Span, Option<Span>),
     UsedLaterInLoop(LaterUseKind, Span, Option<Span>),
     UsedLaterWhenDropped {
@@ -30,7 +30,7 @@ pub(crate) enum BorrowExplanation<'tcx> {
         should_note_order: bool,
     },
     MustBeValidFor {
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         from_closure: bool,
         span: Span,
         region_name: RegionName,
@@ -49,7 +49,7 @@ pub(crate) enum LaterUseKind {
     Other,
 }
 
-impl<'tcx> BorrowExplanation<'tcx> {
+impl<'tcx> BorrowExplanation {
     pub(crate) fn is_explained(&self) -> bool {
         !matches!(self, BorrowExplanation::Unexplained)
     }
@@ -284,7 +284,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
     fn add_lifetime_bound_suggestion_to_diagnostic(
         &self,
         err: &mut Diagnostic,
-        category: &ConstraintCategory<'tcx>,
+        category: &ConstraintCategory,
         span: Span,
         region_name: &RegionName,
     ) {
@@ -316,7 +316,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         &self,
         borrow_region: RegionVid,
         outlived_region: RegionVid,
-    ) -> (ConstraintCategory<'tcx>, bool, Span, Option<RegionName>, Vec<ExtraConstraintInfo>) {
+    ) -> (ConstraintCategory, bool, Span, Option<RegionName>, Vec<ExtraConstraintInfo>) {
         let (blame_constraint, extra_info) = self.regioncx.best_blame_constraint(
             borrow_region,
             NllRegionVariableOrigin::FreeRegion,
@@ -348,7 +348,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         location: Location,
         borrow: &BorrowData<'tcx>,
         kind_place: Option<(WriteKind, Place<'tcx>)>,
-    ) -> BorrowExplanation<'tcx> {
+    ) -> BorrowExplanation {
         let regioncx = &self.regioncx;
         let body: &Body<'_> = &self.body;
         let tcx = self.infcx.tcx;

compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs

@@ -161,7 +161,7 @@ impl OutlivesSuggestionBuilder {
     pub(crate) fn intermediate_suggestion(
         &mut self,
         mbcx: &MirBorrowckCtxt<'_, '_>,
-        errci: &ErrorConstraintInfo<'_>,
+        errci: &ErrorConstraintInfo,
         diag: &mut Diagnostic,
     ) {
         // Emit an intermediate note.

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -2,6 +2,7 @@
 #![deny(rustc::diagnostic_outside_of_impl)]
 //! Error reporting machinery for lifetime errors.
 
+use either::Either;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan};
 use rustc_hir::def_id::DefId;
@@ -16,7 +17,7 @@ use rustc_infer::infer::{
     NllRegionVariableOrigin, RelateParamBound,
 };
 use rustc_middle::hir::place::PlaceBase;
-use rustc_middle::mir::{ConstraintCategory, ReturnConstraint};
+use rustc_middle::mir::{ConstraintCategory, ReturnConstraint, TerminatorKind};
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::Region;
 use rustc_middle::ty::TypeVisitor;
@@ -39,7 +40,7 @@ use crate::{
     MirBorrowckCtxt,
 };
 
-impl<'tcx> ConstraintDescription for ConstraintCategory<'tcx> {
+impl ConstraintDescription for ConstraintCategory {
     fn description(&self) -> &'static str {
         // Must end with a space. Allows for empty names to be provided.
         match self {
@@ -115,7 +116,7 @@ pub(crate) enum RegionErrorKind<'tcx> {
 
 /// Information about the various region constraints involved in a borrow checker error.
 #[derive(Clone, Debug)]
-pub struct ErrorConstraintInfo<'tcx> {
+pub struct ErrorConstraintInfo {
     // fr: outlived_fr
     pub(super) fr: RegionVid,
     pub(super) fr_is_local: bool,
@@ -123,7 +124,7 @@ pub struct ErrorConstraintInfo<'tcx> {
     pub(super) outlived_fr_is_local: bool,
 
     // Category and span for best blame constraint
-    pub(super) category: ConstraintCategory<'tcx>,
+    pub(super) category: ConstraintCategory,
     pub(super) span: Span,
 }
 
@@ -498,7 +499,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     /// ```
     fn report_fnmut_error(
         &self,
-        errci: &ErrorConstraintInfo<'tcx>,
+        errci: &ErrorConstraintInfo,
         kind: ReturnConstraint,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         let ErrorConstraintInfo { outlived_fr, span, .. } = errci;
@@ -571,7 +572,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     #[instrument(level = "debug", skip(self))]
     fn report_escaping_data_error(
         &self,
-        errci: &ErrorConstraintInfo<'tcx>,
+        errci: &ErrorConstraintInfo,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         let ErrorConstraintInfo { span, category, .. } = errci;
 
@@ -675,7 +676,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     /// ```
     fn report_general_error(
         &self,
-        errci: &ErrorConstraintInfo<'tcx>,
+        errci: &ErrorConstraintInfo,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         let ErrorConstraintInfo {
             fr,
@@ -788,7 +789,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         diag: &mut Diagnostic,
         f: Region<'tcx>,
         o: Region<'tcx>,
-        category: &ConstraintCategory<'tcx>,
+        category: &ConstraintCategory,
     ) {
         if !o.is_static() {
             return;
@@ -796,7 +797,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         let tcx = self.infcx.tcx;
 
-        let instance = if let ConstraintCategory::CallArgument(Some(func_ty)) = category {
+        let instance =
+            if let ConstraintCategory::CallArgument(location) = category
+                && let Either::Right(term) = self.body.stmt_at(*location)
+                && let TerminatorKind::Call { func, .. } = &term.kind
+        {
+            let func_ty = func.ty(self.body, tcx);
             let (fn_did, substs) = match func_ty.kind() {
                 ty::FnDef(fn_did, substs) => (fn_did, substs),
                 _ => return,

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -91,7 +91,7 @@ pub struct RegionInferenceContext<'tcx> {
 
     /// Map closure bounds to a `Span` that should be used for error reporting.
     closure_bounds_mapping:
-        FxHashMap<Location, FxHashMap<(RegionVid, RegionVid), (ConstraintCategory<'tcx>, Span)>>,
+        FxHashMap<Location, FxHashMap<(RegionVid, RegionVid), (ConstraintCategory, Span)>>,
 
     /// Map universe indexes to information on why we created it.
     universe_causes: FxHashMap<ty::UniverseIndex, UniverseInfo<'tcx>>,
@@ -267,7 +267,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         member_constraints_in: MemberConstraintSet<'tcx, RegionVid>,
         closure_bounds_mapping: FxHashMap<
             Location,
-            FxHashMap<(RegionVid, RegionVid), (ConstraintCategory<'tcx>, Span)>,
+            FxHashMap<(RegionVid, RegionVid), (ConstraintCategory, Span)>,
         >,
         universe_causes: FxHashMap<ty::UniverseIndex, UniverseInfo<'tcx>>,
         type_tests: Vec<TypeTest<'tcx>>,
@@ -1807,7 +1807,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     pub(crate) fn retrieve_closure_constraint_info(
         &self,
         constraint: OutlivesConstraint<'tcx>,
-    ) -> Option<(ConstraintCategory<'tcx>, Span)> {
+    ) -> Option<(ConstraintCategory, Span)> {
         match constraint.locations {
             Locations::All(_) => None,
             Locations::Single(loc) => {
@@ -1822,7 +1822,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         fr1: RegionVid,
         fr1_origin: NllRegionVariableOrigin,
         fr2: RegionVid,
-    ) -> (ConstraintCategory<'tcx>, ObligationCause<'tcx>) {
+    ) -> (ConstraintCategory, ObligationCause<'tcx>) {
         let BlameConstraint { category, cause, .. } = self
             .best_blame_constraint(fr1, fr1_origin, |r| self.provides_universal_region(r, fr1, fr2))
             .0;
@@ -2362,7 +2362,7 @@ impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx
 
 #[derive(Clone, Debug)]
 pub struct BlameConstraint<'tcx> {
-    pub category: ConstraintCategory<'tcx>,
+    pub category: ConstraintCategory,
     pub from_closure: bool,
     pub cause: ObligationCause<'tcx>,
     pub variance_info: ty::VarianceDiagInfo<'tcx>,

compiler/rustc_borrowck/src/type_check/canonical.rs

@@ -28,7 +28,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     pub(super) fn fully_perform_op<R: fmt::Debug, Op>(
         &mut self,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         op: Op,
     ) -> Fallible<R>
     where
@@ -85,7 +85,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         &mut self,
         trait_ref: ty::TraitRef<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         self.prove_predicate(
             ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
@@ -124,7 +124,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         &mut self,
         predicates: impl IntoIterator<Item = impl ToPredicate<'tcx>>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         for predicate in predicates {
             let predicate = predicate.to_predicate(self.tcx());
@@ -139,7 +139,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         &mut self,
         predicate: ty::Predicate<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         let param_env = self.param_env;
         self.fully_perform_op(
@@ -164,7 +164,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         &mut self,
         value: T,
         location: impl NormalizeLocation,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> T
     where
         T: type_op::normalize::Normalizable<'tcx> + fmt::Display + Copy + 'tcx,

compiler/rustc_borrowck/src/type_check/constraint_conversion.rs

@@ -37,7 +37,7 @@ pub(crate) struct ConstraintConversion<'a, 'tcx> {
     param_env: ty::ParamEnv<'tcx>,
     locations: Locations,
     span: Span,
-    category: ConstraintCategory<'tcx>,
+    category: ConstraintCategory,
     constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
 }
 
@@ -50,7 +50,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
         param_env: ty::ParamEnv<'tcx>,
         locations: Locations,
         span: Span,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
     ) -> Self {
         Self {
@@ -175,7 +175,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
         &mut self,
         sup: ty::RegionVid,
         sub: ty::RegionVid,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         let category = match self.category {
             ConstraintCategory::Boring | ConstraintCategory::BoringNoLocation => category,
@@ -203,7 +203,7 @@ impl<'a, 'b, 'tcx> TypeOutlivesDelegate<'tcx> for &'a mut ConstraintConversion<'
         _origin: SubregionOrigin<'tcx>,
         a: ty::Region<'tcx>,
         b: ty::Region<'tcx>,
-        constraint_category: ConstraintCategory<'tcx>,
+        constraint_category: ConstraintCategory,
     ) {
         let b = self.to_region_vid(b);
         let a = self.to_region_vid(a);

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -942,7 +942,7 @@ pub(crate) struct MirTypeckRegionConstraints<'tcx> {
     pub(crate) member_constraints: MemberConstraintSet<'tcx, RegionVid>,
 
     pub(crate) closure_bounds_mapping:
-        FxHashMap<Location, FxHashMap<(RegionVid, RegionVid), (ConstraintCategory<'tcx>, Span)>>,
+        FxHashMap<Location, FxHashMap<(RegionVid, RegionVid), (ConstraintCategory, Span)>>,
 
     pub(crate) universe_causes: FxHashMap<ty::UniverseIndex, UniverseInfo<'tcx>>,
 
@@ -1133,7 +1133,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     fn push_region_constraints(
         &mut self,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         data: &QueryRegionConstraints<'tcx>,
     ) {
         debug!("constraints generated: {:#?}", data);
@@ -1158,7 +1158,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         sub: Ty<'tcx>,
         sup: Ty<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> Fallible<()> {
         // Use this order of parameters because the sup type is usually the
         // "expected" type in diagnostics.
@@ -1171,7 +1171,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         expected: Ty<'tcx>,
         found: Ty<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> Fallible<()> {
         self.relate_types(expected, ty::Variance::Invariant, found, locations, category)
     }
@@ -1183,7 +1183,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         v: ty::Variance,
         user_ty: &UserTypeProjection,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> Fallible<()> {
         let annotated_type = self.user_type_annotations[user_ty.base].inferred_ty;
         let mut curr_projected_ty = PlaceTy::from_ty(annotated_type);
@@ -1618,19 +1618,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             span_mirbug!(self, term, "call to {:?} with wrong # of args", sig);
         }
 
-        let func_ty = if let TerminatorKind::Call { func, .. } = &term.kind {
-            Some(func.ty(body, self.infcx.tcx))
-        } else {
-            None
-        };
-        debug!(?func_ty);
-
         for (n, (fn_arg, op_arg)) in iter::zip(sig.inputs(), args).enumerate() {
             let op_arg_ty = op_arg.ty(body, self.tcx());
 
             let op_arg_ty = self.normalize(op_arg_ty, term_location);
             let category = if from_hir_call {
-                ConstraintCategory::CallArgument(func_ty)
+                ConstraintCategory::CallArgument(term_location)
             } else {
                 ConstraintCategory::Boring
             };

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -28,7 +28,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         v: ty::Variance,
         b: Ty<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> Fallible<()> {
         TypeRelating::new(
             self.infcx,
@@ -45,7 +45,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         a: ty::SubstsRef<'tcx>,
         b: ty::SubstsRef<'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) -> Fallible<()> {
         TypeRelating::new(
             self.infcx,
@@ -64,7 +64,7 @@ struct NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
     locations: Locations,
 
     /// What category do we assign the resulting `'a: 'b` relationships?
-    category: ConstraintCategory<'tcx>,
+    category: ConstraintCategory,
 
     /// Information so that error reporting knows what types we are relating
     /// when reporting a bound region error.
@@ -75,7 +75,7 @@ impl<'me, 'bccx, 'tcx> NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
     fn new(
         type_checker: &'me mut TypeChecker<'bccx, 'tcx>,
         locations: Locations,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
         universe_info: UniverseInfo<'tcx>,
     ) -> Self {
         Self { type_checker, locations, category, universe_info }

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

@@ -632,7 +632,7 @@ impl<'tcx> InferCtxt<'tcx> {
 /// creates query region constraints.
 pub fn make_query_region_constraints<'tcx>(
     tcx: TyCtxt<'tcx>,
-    outlives_obligations: impl Iterator<Item = (Ty<'tcx>, ty::Region<'tcx>, ConstraintCategory<'tcx>)>,
+    outlives_obligations: impl Iterator<Item = (Ty<'tcx>, ty::Region<'tcx>, ConstraintCategory)>,
     region_constraints: &RegionConstraintData<'tcx>,
 ) -> QueryRegionConstraints<'tcx> {
     let RegionConstraintData { constraints, verifys, givens, member_constraints } =

compiler/rustc_infer/src/infer/mod.rs

@@ -425,7 +425,7 @@ pub enum SubregionOrigin<'tcx> {
 static_assert_size!(SubregionOrigin<'_>, 32);
 
 impl<'tcx> SubregionOrigin<'tcx> {
-    pub fn to_constraint_category(&self) -> ConstraintCategory<'tcx> {
+    pub fn to_constraint_category(&self) -> ConstraintCategory {
         match self {
             Self::Subtype(type_trace) => type_trace.cause.to_constraint_category(),
             Self::AscribeUserTypeProvePredicate(span) => ConstraintCategory::Predicate(*span),

compiler/rustc_infer/src/infer/outlives/obligations.rs

@@ -210,7 +210,7 @@ pub trait TypeOutlivesDelegate<'tcx> {
         origin: SubregionOrigin<'tcx>,
         a: ty::Region<'tcx>,
         b: ty::Region<'tcx>,
-        constraint_category: ConstraintCategory<'tcx>,
+        constraint_category: ConstraintCategory,
     );
 
     fn push_verify(
@@ -259,7 +259,7 @@ where
         origin: infer::SubregionOrigin<'tcx>,
         ty: Ty<'tcx>,
         region: ty::Region<'tcx>,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         assert!(!ty.has_escaping_bound_vars());
 
@@ -273,7 +273,7 @@ where
         origin: infer::SubregionOrigin<'tcx>,
         components: &[Component<'tcx>],
         region: ty::Region<'tcx>,
-        category: ConstraintCategory<'tcx>,
+        category: ConstraintCategory,
     ) {
         for component in components.iter() {
             let origin = origin.clone();
@@ -529,7 +529,7 @@ impl<'cx, 'tcx> TypeOutlivesDelegate<'tcx> for &'cx InferCtxt<'tcx> {
         origin: SubregionOrigin<'tcx>,
         a: ty::Region<'tcx>,
         b: ty::Region<'tcx>,
-        _constraint_category: ConstraintCategory<'tcx>,
+        _constraint_category: ConstraintCategory,
     ) {
         self.sub_regions(origin, a, b)
     }

compiler/rustc_middle/src/infer/canonical.rs

@@ -302,10 +302,8 @@ impl<'tcx, V> Canonical<'tcx, V> {
     }
 }
 
-pub type QueryOutlivesConstraint<'tcx> = (
+pub type QueryOutlivesConstraint<'tcx> =
-    ty::Binder<'tcx, ty::OutlivesPredicate<GenericArg<'tcx>, Region<'tcx>>>,
+    (ty::Binder<'tcx, ty::OutlivesPredicate<GenericArg<'tcx>, Region<'tcx>>>, ConstraintCategory);
-    ConstraintCategory<'tcx>,
-);
 
 TrivialTypeTraversalAndLiftImpls! {
     for <'tcx> {

compiler/rustc_middle/src/mir/mod.rs

@@ -2875,7 +2875,7 @@ fn pretty_print_const_value<'tcx>(
 /// `Location` represents the position of the start of the statement; or, if
 /// `statement_index` equals the number of statements, then the start of the
 /// terminator.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd, HashStable)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd, HashStable, TyEncodable, TyDecodable)]
 pub struct Location {
     /// The block that the location is within.
     pub block: BasicBlock,

compiler/rustc_middle/src/mir/query.rs

@@ -15,7 +15,7 @@ use smallvec::SmallVec;
 use std::cell::Cell;
 use std::fmt::{self, Debug};
 
-use super::{Field, SourceInfo};
+use super::{Field, Location, SourceInfo};
 
 #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable, Debug)]
 pub enum UnsafetyViolationKind {
@@ -314,12 +314,12 @@ pub struct ClosureOutlivesRequirement<'tcx> {
     pub blame_span: Span,
 
     // ... due to this reason.
-    pub category: ConstraintCategory<'tcx>,
+    pub category: ConstraintCategory,
 }
 
 // Make sure this enum doesn't unintentionally grow
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(ConstraintCategory<'_>, 16);
+rustc_data_structures::static_assert_size!(ConstraintCategory, 16);
 
 /// Outlives-constraints can be categorized to determine whether and why they
 /// are interesting (for error reporting). Order of variants indicates sort
@@ -327,8 +327,8 @@ rustc_data_structures::static_assert_size!(ConstraintCategory<'_>, 16);
 ///
 /// See also `rustc_const_eval::borrow_check::constraints`.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Hash)]
-#[derive(TyEncodable, TyDecodable, HashStable, Lift, TypeVisitable, TypeFoldable)]
+#[derive(TyEncodable, TyDecodable, HashStable)]
-pub enum ConstraintCategory<'tcx> {
+pub enum ConstraintCategory {
     Return(ReturnConstraint),
     Yield,
     UseAsConst,
@@ -342,7 +342,7 @@ pub enum ConstraintCategory<'tcx> {
     ClosureBounds,
 
     /// Contains the function type if available.
-    CallArgument(Option<Ty<'tcx>>),
+    CallArgument(Location),
     CopyBound,
     SizedBound,
     Assignment,
@@ -368,6 +368,10 @@ pub enum ConstraintCategory<'tcx> {
     Internal,
 }
 
+TrivialTypeTraversalAndLiftImpls! {
+    ConstraintCategory,
+}
+
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Hash)]
 #[derive(TyEncodable, TyDecodable, HashStable, TypeVisitable, TypeFoldable)]
 pub enum ReturnConstraint {

compiler/rustc_middle/src/query/mod.rs

@@ -1207,9 +1207,9 @@ rustc_queries! {
     }
 
     query own_existential_vtable_entries(
-        key: ty::PolyExistentialTraitRef<'tcx>
+        key: DefId
     ) -> &'tcx [DefId] {
-        desc { |tcx| "finding all existential vtable entries for trait `{}`", tcx.def_path_str(key.def_id()) }
+        desc { |tcx| "finding all existential vtable entries for trait `{}`", tcx.def_path_str(key) }
     }
 
     query vtable_entries(key: ty::PolyTraitRef<'tcx>)

compiler/rustc_middle/src/traits/mod.rs

@@ -185,7 +185,7 @@ impl<'tcx> ObligationCause<'tcx> {
         self
     }
 
-    pub fn to_constraint_category(&self) -> ConstraintCategory<'tcx> {
+    pub fn to_constraint_category(&self) -> ConstraintCategory {
         match self.code() {
             MatchImpl(cause, _) => cause.to_constraint_category(),
             AscribeUserTypeProvePredicate(predicate_span) => {

compiler/rustc_middle/src/ty/consts/kind.rs

@@ -5,6 +5,7 @@ use crate::mir::interpret::{AllocId, ConstValue, Scalar};
 use crate::ty::subst::{InternalSubsts, SubstsRef};
 use crate::ty::ParamEnv;
 use crate::ty::{self, TyCtxt, TypeVisitable};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
 use rustc_macros::HashStable;
@@ -108,7 +109,6 @@ impl<'tcx> ConstKind<'tcx> {
 
 /// An inference variable for a const, for use in const generics.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, TyEncodable, TyDecodable, Hash)]
-#[derive(HashStable)]
 pub enum InferConst<'tcx> {
     /// Infer the value of the const.
     Var(ty::ConstVid<'tcx>),
@@ -116,6 +116,15 @@ pub enum InferConst<'tcx> {
     Fresh(u32),
 }
 
+impl<CTX> HashStable<CTX> for InferConst<'_> {
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        match self {
+            InferConst::Var(_) => panic!("const variables should not be hashed: {self:?}"),
+            InferConst::Fresh(i) => i.hash_stable(hcx, hasher),
+        }
+    }
+}
+
 enum EvalMode {
     Typeck,
     Mir,

compiler/rustc_middle/src/ty/context.rs

@@ -198,9 +198,9 @@ impl<'tcx> CtxtInterners<'tcx> {
                 .intern(kind, |kind| {
                     let flags = super::flags::FlagComputation::for_kind(&kind);
 
-                    // It's impossible to hash inference regions (and will ICE), so we don't need to try to cache them.
+                    // It's impossible to hash inference variables (and will ICE), so we don't need to try to cache them.
                     // Without incremental, we rarely stable-hash types, so let's not do it proactively.
-                    let stable_hash = if flags.flags.intersects(TypeFlags::HAS_RE_INFER)
+                    let stable_hash = if flags.flags.intersects(TypeFlags::NEEDS_INFER)
                         || sess.opts.incremental.is_none()
                     {
                         Fingerprint::ZERO

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -764,12 +764,9 @@ fn dump_vtable_entries<'tcx>(
     });
 }
 
-fn own_existential_vtable_entries<'tcx>(
+fn own_existential_vtable_entries<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId) -> &'tcx [DefId] {
-    tcx: TyCtxt<'tcx>,
-    trait_ref: ty::PolyExistentialTraitRef<'tcx>,
-) -> &'tcx [DefId] {
     let trait_methods = tcx
-        .associated_items(trait_ref.def_id())
+        .associated_items(trait_def_id)
         .in_definition_order()
         .filter(|item| item.kind == ty::AssocKind::Fn);
     // Now list each method's DefId (for within its trait).
@@ -778,7 +775,7 @@ fn own_existential_vtable_entries<'tcx>(
         let def_id = trait_method.def_id;
 
         // Some methods cannot be called on an object; skip those.
-        if !is_vtable_safe_method(tcx, trait_ref.def_id(), &trait_method) {
+        if !is_vtable_safe_method(tcx, trait_def_id, &trait_method) {
             debug!("own_existential_vtable_entry: not vtable safe");
             return None;
         }
@@ -810,7 +807,7 @@ fn vtable_entries<'tcx>(
 
                 // Lookup the shape of vtable for the trait.
                 let own_existential_entries =
-                    tcx.own_existential_vtable_entries(existential_trait_ref);
+                    tcx.own_existential_vtable_entries(existential_trait_ref.def_id());
 
                 let own_entries = own_existential_entries.iter().copied().map(|def_id| {
                     debug!("vtable_entries: trait_method={:?}", def_id);

compiler/rustc_trait_selection/src/traits/util.rs

@@ -268,10 +268,7 @@ pub fn count_own_vtable_entries<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>,
 ) -> usize {
-    let existential_trait_ref =
+    tcx.own_existential_vtable_entries(trait_ref.def_id()).len()
-        trait_ref.map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref));
-    let existential_trait_ref = tcx.erase_regions(existential_trait_ref);
-    tcx.own_existential_vtable_entries(existential_trait_ref).len()
 }
 
 /// Given an upcast trait object described by `object`, returns the
@@ -282,15 +279,10 @@ pub fn get_vtable_index_of_object_method<'tcx, N>(
     object: &super::ImplSourceObjectData<'tcx, N>,
     method_def_id: DefId,
 ) -> Option<usize> {
-    let existential_trait_ref = object
-        .upcast_trait_ref
-        .map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref));
-    let existential_trait_ref = tcx.erase_regions(existential_trait_ref);
-
     // Count number of methods preceding the one we are selecting and
     // add them to the total offset.
     if let Some(index) = tcx
-        .own_existential_vtable_entries(existential_trait_ref)
+        .own_existential_vtable_entries(object.upcast_trait_ref.def_id())
         .iter()
         .copied()
         .position(|def_id| def_id == method_def_id)

compiler/rustc_type_ir/src/lib.rs

@@ -675,9 +675,9 @@ impl<CTX> HashStable<CTX> for InferTy {
         use InferTy::*;
         discriminant(self).hash_stable(ctx, hasher);
         match self {
-            TyVar(v) => v.as_u32().hash_stable(ctx, hasher),
+            TyVar(_) | IntVar(_) | FloatVar(_) => {
-            IntVar(v) => v.index.hash_stable(ctx, hasher),
+                panic!("type variables should not be hashed: {self:?}")
-            FloatVar(v) => v.index.hash_stable(ctx, hasher),
+            }
             FreshTy(v) | FreshIntTy(v) | FreshFloatTy(v) => v.hash_stable(ctx, hasher),
         }
     }

compiler/rustc_type_ir/src/sty.rs

@@ -1332,8 +1332,8 @@ where
             RePlaceholder(p) => {
                 p.hash_stable(hcx, hasher);
             }
-            ReVar(reg) => {
+            ReVar(_) => {
-                reg.hash_stable(hcx, hasher);
+                panic!("region variables should not be hashed: {self:?}")
             }
         }
     }

src/test/ui/async-await/issues/issue-72312.stderr

@@ -1,5 +1,5 @@
 error[E0521]: borrowed data escapes outside of associated function
-  --> $DIR/issue-72312.rs:12:9
+  --> $DIR/issue-72312.rs:12:24
    |
 LL |       pub async fn start(&self) {
    |                          -----
@@ -7,16 +7,17 @@ LL |       pub async fn start(&self) {
    |                          `self` is a reference that is only valid in the associated function body
    |                          let's call the lifetime of this reference `'1`
 ...
-LL | /         require_static(async move {
+LL |           require_static(async move {
+   |  ________________________^
 LL | |
 LL | |
 LL | |
 LL | |             &self;
 LL | |         });
-   | |          ^
+   | |         ^
-   | |          |
+   | |         |
-   | |__________`self` escapes the associated function body here
+   | |_________`self` escapes the associated function body here
-   |            argument requires that `'1` must outlive `'static`
+   |           argument requires that `'1` must outlive `'static`
 
 error: aborting due to previous error
 

src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr

@@ -53,15 +53,14 @@ LL | fn case2() {
 error[E0597]: `a` does not live long enough
   --> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:30:26
    |
-LL |       let cell = Cell::new(&a);
+LL |     let cell = Cell::new(&a);
-   |                            ^^ borrowed value does not live long enough
+   |                ----------^^-
+   |                |         |
+   |                |         borrowed value does not live long enough
+   |                argument requires that `a` is borrowed for `'static`
 ...
-LL | /     foo(cell, |cell_a, cell_x| {
+LL | }
-LL | |         cell_x.set(cell_a.get()); // forces 'a: 'x, implies 'a = 'static -> borrow error
+   | - `a` dropped here while still borrowed
-LL | |     })
-   | |______- argument requires that `a` is borrowed for `'static`
-LL |   }
-   |   - `a` dropped here while still borrowed
 
 error: aborting due to 2 previous errors
 

src/test/ui/nll/user-annotations/adt-nullary-enums.stderr

@@ -1,14 +1,14 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-nullary-enums.rs:33:41
    |
-LL | /     combine(
+LL |         SomeEnum::SomeVariant(Cell::new(&c)),
-LL | |         SomeEnum::SomeVariant(Cell::new(&c)),
+   |                               ----------^^-
-   | |                                         ^^ borrowed value does not live long enough
+   |                               |         |
-LL | |         SomeEnum::SomeOtherVariant::<Cell<&'static u32>>,
+   |                               |         borrowed value does not live long enough
-LL | |     );
+   |                               argument requires that `c` is borrowed for `'static`
-   | |_____- argument requires that `c` is borrowed for `'static`
+...
-LL |   }
+LL | }
-   |   - `c` dropped here while still borrowed
+   | - `c` dropped here while still borrowed
 
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-nullary-enums.rs:41:41