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

[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`

Author: bors

RELEASES.md

@@ -1,3 +1,21 @@
+Version 1.62.1 (2022-07-19)
+==========================
+
+Rust 1.62.1 addresses a few recent regressions in the compiler and standard
+library, and also mitigates a CPU vulnerability on Intel SGX.
+
+* [The compiler fixed unsound function coercions involving `impl Trait` return types.][98608]
+* [The compiler fixed an incremental compilation bug with `async fn` lifetimes.][98890]
+* [Windows added a fallback for overlapped I/O in synchronous reads and writes.][98950]
+* [The `x86_64-fortanix-unknown-sgx` target added a mitigation for the
+  MMIO stale data vulnerability][98126], advisory [INTEL-SA-00615].
+
+[98608]: https://github.com/rust-lang/rust/issues/98608
+[98890]: https://github.com/rust-lang/rust/issues/98890
+[98950]: https://github.com/rust-lang/rust/pull/98950
+[98126]: https://github.com/rust-lang/rust/pull/98126
+[INTEL-SA-00615]: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
+
 Version 1.62.0 (2022-06-30)
 ==========================
 

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);
     }

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

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 {

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) });

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>>,

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>>>,
 }

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

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,
         }
     }
 }

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>,
 }