Auto merge of #99299 - Mark-Simulacrum:stable-next, r=Mark-Simulacrum 1.62.1

[stable] 1.62.1 release

This bundles:

*  Windows: Fallback for overlapped I/O #98950
*  don't succeed evaluate_obligation query if new opaque types were registered #98614
*  Mitigate MMIO stale data vulnerability #98126
*  Return a FxIndexSet in is_late_bound query. #99219

Also bumps the version number to 1.62.1 and includes a short release notes section for the release.

r? `@Mark-Simulacrum`

14 files changed, 42 insertions, 20 deletions

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index c9121f7d348..989cc551a82 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -929,6 +929,10 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             .region_constraints_added_in_snapshot(&snapshot.undo_snapshot)
     }
 
+    pub fn opaque_types_added_in_snapshot(&self, snapshot: &CombinedSnapshot<'a, 'tcx>) -> bool {
+        self.inner.borrow().undo_log.opaque_types_in_snapshot(&snapshot.undo_snapshot)
+    }
+
     pub fn add_given(&self, sub: ty::Region<'tcx>, sup: ty::RegionVid) {
         self.inner.borrow_mut().unwrap_region_constraints().add_given(sub, sup);
     }
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index 92c0ed84057..3b9b6f7a2af 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -99,7 +99,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
         let (a, b) = if a_is_expected { (a, b) } else { (b, a) };
         let process = |a: Ty<'tcx>, b: Ty<'tcx>| match *a.kind() {
-            ty::Opaque(def_id, substs) => {
+            ty::Opaque(def_id, substs) if def_id.is_local() => {
                 let origin = if self.defining_use_anchor.is_some() {
                     // Check that this is `impl Trait` type is
                     // declared by `parent_def_id` -- i.e., one whose
diff --git a/compiler/rustc_infer/src/infer/undo_log.rs b/compiler/rustc_infer/src/infer/undo_log.rs
index 1b696f21cbc..74a26ebc39f 100644
--- a/compiler/rustc_infer/src/infer/undo_log.rs
+++ b/compiler/rustc_infer/src/infer/undo_log.rs
@@ -185,6 +185,10 @@ impl<'tcx> InferCtxtUndoLogs<'tcx> {
         })
     }
 
+    pub(crate) fn opaque_types_in_snapshot(&self, s: &Snapshot<'tcx>) -> bool {
+        self.logs[s.undo_len..].iter().any(|log| matches!(log, UndoLog::OpaqueTypes(..)))
+    }
+
     pub(crate) fn region_constraints(
         &self,
     ) -> impl Iterator<Item = &'_ region_constraints::UndoLog<'tcx>> + Clone {
diff --git a/compiler/rustc_infer/src/traits/project.rs b/compiler/rustc_infer/src/traits/project.rs
index b84ed3dc689..18469208731 100644
--- a/compiler/rustc_infer/src/traits/project.rs
+++ b/compiler/rustc_infer/src/traits/project.rs
@@ -203,7 +203,7 @@ impl<'tcx> ProjectionCache<'_, 'tcx> {
             Some(&ProjectionCacheEntry::NormalizedTy { ref ty, complete: _ }) => {
                 info!("ProjectionCacheEntry::complete({:?}) - completing {:?}", key, ty);
                 let mut ty = ty.clone();
-                if result == EvaluationResult::EvaluatedToOk {
+                if result.must_apply_considering_regions() {
                     ty.obligations = vec![];
                 }
                 map.insert(key, ProjectionCacheEntry::NormalizedTy { ty, complete: Some(result) });
diff --git a/compiler/rustc_middle/src/arena.rs b/compiler/rustc_middle/src/arena.rs
index 7c90cbb9092..c1ec5d68a7b 100644
--- a/compiler/rustc_middle/src/arena.rs
+++ b/compiler/rustc_middle/src/arena.rs
@@ -85,6 +85,7 @@ macro_rules! arena_types {
             [] attribute: rustc_ast::Attribute,
             [] name_set: rustc_data_structures::fx::FxHashSet<rustc_span::symbol::Symbol>,
             [] hir_id_set: rustc_hir::HirIdSet,
+            [] late_bound_lifetimes: rustc_data_structures::fx::FxIndexSet<rustc_hir::def_id::LocalDefId>,
 
             // Interned types
             [] tys: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::TyS<'tcx>>,
diff --git a/compiler/rustc_middle/src/middle/resolve_lifetime.rs b/compiler/rustc_middle/src/middle/resolve_lifetime.rs
index 70586cefaee..11ce6313147 100644
--- a/compiler/rustc_middle/src/middle/resolve_lifetime.rs
+++ b/compiler/rustc_middle/src/middle/resolve_lifetime.rs
@@ -2,7 +2,7 @@
 
 use crate::ty;
 
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::ItemLocalId;
 use rustc_macros::HashStable;
@@ -64,7 +64,7 @@ pub struct ResolveLifetimes {
     /// Set of lifetime def ids that are late-bound; a region can
     /// be late-bound if (a) it does NOT appear in a where-clause and
     /// (b) it DOES appear in the arguments.
-    pub late_bound: FxHashMap<LocalDefId, FxHashSet<LocalDefId>>,
+    pub late_bound: FxHashMap<LocalDefId, FxIndexSet<LocalDefId>>,
 
     pub late_bound_vars: FxHashMap<LocalDefId, FxHashMap<ItemLocalId, Vec<ty::BoundVariableKind>>>,
 }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 6d7ec247d04..a23ff302a40 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1537,7 +1537,7 @@ rustc_queries! {
         Option<&'tcx FxHashMap<ItemLocalId, Region>> {
         desc { "looking up a named region" }
     }
-    query is_late_bound_map(_: LocalDefId) -> Option<(LocalDefId, &'tcx FxHashSet<LocalDefId>)> {
+    query is_late_bound_map(_: LocalDefId) -> Option<(LocalDefId, &'tcx FxIndexSet<LocalDefId>)> {
         desc { "testing if a region is late bound" }
     }
     /// For a given item (like a struct), gets the default lifetimes to be used
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index ffa70cddbd5..854dd215a37 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -176,6 +176,10 @@ pub enum EvaluationResult {
     EvaluatedToOk,
     /// Evaluation successful, but there were unevaluated region obligations.
     EvaluatedToOkModuloRegions,
+    /// Evaluation successful, but need to rerun because opaque types got
+    /// hidden types assigned without it being known whether the opaque types
+    /// are within their defining scope
+    EvaluatedToOkModuloOpaqueTypes,
     /// Evaluation is known to be ambiguous -- it *might* hold for some
     /// assignment of inference variables, but it might not.
     ///
@@ -252,9 +256,11 @@ impl EvaluationResult {
 
     pub fn may_apply(self) -> bool {
         match self {
-            EvaluatedToOk | EvaluatedToOkModuloRegions | EvaluatedToAmbig | EvaluatedToUnknown => {
-                true
-            }
+            EvaluatedToOkModuloOpaqueTypes
+            | EvaluatedToOk
+            | EvaluatedToOkModuloRegions
+            | EvaluatedToAmbig
+            | EvaluatedToUnknown => true,
 
             EvaluatedToErr | EvaluatedToRecur => false,
         }
@@ -264,7 +270,11 @@ impl EvaluationResult {
         match self {
             EvaluatedToUnknown | EvaluatedToRecur => true,
 
-            EvaluatedToOk | EvaluatedToOkModuloRegions | EvaluatedToAmbig | EvaluatedToErr => false,
+            EvaluatedToOkModuloOpaqueTypes
+            | EvaluatedToOk
+            | EvaluatedToOkModuloRegions
+            | EvaluatedToAmbig
+            | EvaluatedToErr => false,
         }
     }
 }
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 1c552591b11..a254979162e 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1065,6 +1065,7 @@ impl<'tcx> InstantiatedPredicates<'tcx> {
     Lift
 )]
 pub struct OpaqueTypeKey<'tcx> {
+    // FIXME(oli-obk): make this a LocalDefId
     pub def_id: DefId,
     pub substs: SubstsRef<'tcx>,
 }
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index fb937ded65a..1bb49a59ba4 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -36,7 +36,7 @@ use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, T
 use rustc_ast as ast;
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_attr as attr;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::steal::Steal;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index ff75e4eae35..9b4184840bd 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -8,7 +8,7 @@
 
 use crate::late::diagnostics::{ForLifetimeSpanType, MissingLifetimeSpot};
 use rustc_ast::walk_list;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::{struct_span_err, Applicability, Diagnostic};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -482,6 +482,11 @@ fn convert_named_region_map(tcx: TyCtxt<'_>, named_region_map: NamedRegionMap) -
         let def_id = tcx.hir().local_def_id(hir_id);
         map.insert(def_id);
     }
+    for (_, late_bound) in &mut rl.late_bound {
+        late_bound.sort_by(|&a, &b| {
+            tcx.def_path_hash(a.to_def_id()).cmp(&tcx.def_path_hash(b.to_def_id()))
+        });
+    }
     for (hir_id, v) in named_region_map.late_bound_vars {
         let map = rl.late_bound_vars.entry(hir_id.owner).or_default();
         map.insert(hir_id.local_id, v);
@@ -540,7 +545,7 @@ fn item_for(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> LocalDefId {
 fn is_late_bound_map<'tcx>(
     tcx: TyCtxt<'tcx>,
     def_id: LocalDefId,
-) -> Option<(LocalDefId, &'tcx FxHashSet<LocalDefId>)> {
+) -> Option<(LocalDefId, &'tcx FxIndexSet<LocalDefId>)> {
     match tcx.def_kind(def_id) {
         DefKind::AnonConst | DefKind::InlineConst => {
             let mut def_id = tcx.local_parent(def_id);
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index d20ba99ebc9..60cb5914dad 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -761,6 +761,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             Ok(
                 EvaluationResult::EvaluatedToOk
                 | EvaluationResult::EvaluatedToOkModuloRegions
+                | EvaluationResult::EvaluatedToOkModuloOpaqueTypes
                 | EvaluationResult::EvaluatedToAmbig,
             ) => {}
             _ => return false,
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 1c9f83f8f34..ed4877638bf 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -388,6 +388,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Err(_) => return Ok(EvaluatedToErr),
             }
 
+            if self.infcx.opaque_types_added_in_snapshot(snapshot) {
+                return Ok(result.max(EvaluatedToOkModuloOpaqueTypes));
+            }
+
             match self.infcx.region_constraints_added_in_snapshot(snapshot) {
                 None => Ok(result),
                 Some(_) => Ok(result.max(EvaluatedToOkModuloRegions)),
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index c63e9c31d53..a46729f229e 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -61,14 +61,6 @@ bitflags! {
                                           | TypeFlags::HAS_CT_INFER.bits
                                           | TypeFlags::HAS_TY_PLACEHOLDER.bits
                                           | TypeFlags::HAS_CT_PLACEHOLDER.bits
-                                          // The `evaluate_obligation` query does not return further
-                                          // obligations. If it evaluates an obligation with an opaque
-                                          // type, that opaque type may get compared to another type,
-                                          // constraining it. We would lose this information.
-                                          // FIXME: differentiate between crate-local opaque types
-                                          // and opaque types from other crates, as only opaque types
-                                          // from the local crate can possibly be a local name
-                                          | TypeFlags::HAS_TY_OPAQUE.bits
                                           // We consider 'freshened' types and constants
                                           // to depend on a particular fn.
                                           // The freshening process throws away information,