An attempt at rebasing on upstream

Author: amandasystems

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -379,7 +379,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                         self.body.source.def_id().expect_local(),
                         type_test_span,
                         Some(origin),
-                        generic_kind,
+                        self.name_regions(self.infcx.tcx, generic_kind),
                         lower_bound_region,
                     ));
                 }

compiler/rustc_borrowck/src/member_constraints.rs

@@ -1,7 +1,6 @@
 use std::hash::Hash;
 use std::ops::Index;
 
-use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::ty::{self, Ty};

compiler/rustc_borrowck/src/nll.rs

@@ -28,10 +28,10 @@ use crate::borrow_set::BorrowSet;
 use crate::consumers::ConsumerOptions;
 use crate::diagnostics::{BorrowckDiagnosticsBuffer, RegionErrors};
 use crate::eliminate_placeholders::rewrite_higher_kinded_outlives_as_constraints;
+use crate::polonius::PoloniusDiagnosticsContext;
 use crate::polonius::legacy::{
     PoloniusFacts, PoloniusFactsExt, PoloniusLocationTable, PoloniusOutput,
 };
-use crate::polonius::{LocalizedOutlivesConstraintSet, PoloniusDiagnosticsContext};
 use crate::region_infer::RegionInferenceContext;
 use crate::type_check::{self, MirTypeckRegionConstraints, MirTypeckResults};
 use crate::universal_regions::UniversalRegions;

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1786,16 +1786,14 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         // FIXME: the performance of this is Not Great, and the logic
         // should be folded into the search itself if possible.
         for constraint in path.iter() {
-            let ConstraintCategory::IllegalPlaceholder(culprit_from, culprit_to) =
-                constraint.category
-            else {
+            let ConstraintCategory::IllegalPlaceholder(cl_fr, culprit) = constraint.category else {
                 continue;
             };
 
-            debug!("{culprit_from:?}: {culprit_to:?} is the reason {from:?}: 'static!");
+            debug!("{culprit:?} is the reason {from:?}: 'static!");
             // FIXME: think: this may be for transitive reasons and
             // we may have to do this arbitrarily many times. Or may we?
-            return self.find_constraint_path_to(culprit_from, |r| r == culprit_to, false).unwrap();
+            return self.find_constraint_path_to(cl_fr, |r| r == culprit, false).unwrap();
         }
 
         // No funny business; just return the path!

compiler/rustc_middle/src/mir/query.rs

@@ -10,12 +10,12 @@ use rustc_index::bit_set::BitMatrix;
 use rustc_index::{Idx, IndexVec};
 use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 use rustc_span::{Span, Symbol};
-use rustc_type_ir::RegionVid;
+//use rustc_type_ir::RegionVid;
 use smallvec::SmallVec;
 
 use super::{ConstValue, SourceInfo};
 use crate::ty::fold::fold_regions;
-use crate::ty::{self, CoroutineArgsExt, OpaqueHiddenType, Ty, TyCtxt};
+use crate::ty::{self, CoroutineArgsExt, OpaqueHiddenType, RegionVid, Ty, TyCtxt};
 
 rustc_index::newtype_index! {
     #[derive(HashStable)]
@@ -238,7 +238,14 @@ pub enum ConstraintCategory<'tcx> {
     /// An internal constraint derived from an illegal placeholder relation
     /// to this region. The arguments are a source -> drain of a path
     /// that caused the problem, used when reporting errors.
-    IllegalPlaceholder(RegionVid, RegionVid),
+    IllegalPlaceholder(
+        #[type_foldable(identity)]
+        #[type_visitable(ignore)]
+        RegionVid,
+        #[type_foldable(identity)]
+        #[type_visitable(ignore)]
+        RegionVid,
+    ),
 }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]