Auto merge of #141292 - matthiaskrgr:rollup-9nhhk7k, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #139419 (Error on recursive opaque ty in HIR typeck)
 - #141236 (Resolved issue with mismatched types triggering ICE in certain scenarios)
 - #141253 (Warning added when dependency crate has async drop types, and the feature is disabled)
 - #141269 (rustc-dev-guide subtree update)
 - #141275 (`gather_locals`: only visit guard pattern guards when checking the guard)
 - #141279 (`lower_to_hir` cleanups)
 - #141285 (Add tick to `RePlaceholder` debug output)

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

8 files changed, 114 insertions, 85 deletions

diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index f48a571b86a..e98d6c50ee7 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -70,44 +70,32 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
         }
     }
 
-    pub(super) fn lower_node(&mut self, def_id: LocalDefId) -> hir::MaybeOwner<'hir> {
+    pub(super) fn lower_node(&mut self, def_id: LocalDefId) {
         let owner = self.owners.ensure_contains_elem(def_id, || hir::MaybeOwner::Phantom);
         if let hir::MaybeOwner::Phantom = owner {
             let node = self.ast_index[def_id];
             match node {
                 AstOwner::NonOwner => {}
-                AstOwner::Crate(c) => self.lower_crate(c),
-                AstOwner::Item(item) => self.lower_item(item),
-                AstOwner::AssocItem(item, ctxt) => self.lower_assoc_item(item, ctxt),
-                AstOwner::ForeignItem(item) => self.lower_foreign_item(item),
+                AstOwner::Crate(c) => {
+                    debug_assert_eq!(self.resolver.node_id_to_def_id[&CRATE_NODE_ID], CRATE_DEF_ID);
+                    self.with_lctx(CRATE_NODE_ID, |lctx| {
+                        let module = lctx.lower_mod(&c.items, &c.spans);
+                        // FIXME(jdonszelman): is dummy span ever a problem here?
+                        lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs, DUMMY_SP);
+                        hir::OwnerNode::Crate(module)
+                    })
+                }
+                AstOwner::Item(item) => {
+                    self.with_lctx(item.id, |lctx| hir::OwnerNode::Item(lctx.lower_item(item)))
+                }
+                AstOwner::AssocItem(item, ctxt) => {
+                    self.with_lctx(item.id, |lctx| lctx.lower_assoc_item(item, ctxt))
+                }
+                AstOwner::ForeignItem(item) => self.with_lctx(item.id, |lctx| {
+                    hir::OwnerNode::ForeignItem(lctx.lower_foreign_item(item))
+                }),
             }
         }
-
-        self.owners[def_id]
-    }
-
-    #[instrument(level = "debug", skip(self, c))]
-    fn lower_crate(&mut self, c: &Crate) {
-        debug_assert_eq!(self.resolver.node_id_to_def_id[&CRATE_NODE_ID], CRATE_DEF_ID);
-        self.with_lctx(CRATE_NODE_ID, |lctx| {
-            let module = lctx.lower_mod(&c.items, &c.spans);
-            // FIXME(jdonszelman): is dummy span ever a problem here?
-            lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs, DUMMY_SP);
-            hir::OwnerNode::Crate(module)
-        })
-    }
-
-    #[instrument(level = "debug", skip(self))]
-    fn lower_item(&mut self, item: &Item) {
-        self.with_lctx(item.id, |lctx| hir::OwnerNode::Item(lctx.lower_item(item)))
-    }
-
-    fn lower_assoc_item(&mut self, item: &AssocItem, ctxt: AssocCtxt) {
-        self.with_lctx(item.id, |lctx| lctx.lower_assoc_item(item, ctxt))
-    }
-
-    fn lower_foreign_item(&mut self, item: &ForeignItem) {
-        self.with_lctx(item.id, |lctx| hir::OwnerNode::ForeignItem(lctx.lower_foreign_item(item)))
     }
 }
 
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 19095f2e01e..422e79ca82f 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -444,14 +444,14 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
         tcx.definitions_untracked().def_index_count(),
     );
 
+    let mut lowerer = item::ItemLowerer {
+        tcx,
+        resolver: &mut resolver,
+        ast_index: &ast_index,
+        owners: &mut owners,
+    };
     for def_id in ast_index.indices() {
-        item::ItemLowerer {
-            tcx,
-            resolver: &mut resolver,
-            ast_index: &ast_index,
-            owners: &mut owners,
-        }
-        .lower_node(def_id);
+        lowerer.lower_node(def_id);
     }
 
     drop(ast_index);
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index d1bc54ed73e..8182851a015 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -84,7 +84,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         self.annotate_expected_due_to_let_ty(err, expr, error);
         self.annotate_loop_expected_due_to_inference(err, expr, error);
-        if self.annotate_mut_binding_to_immutable_binding(err, expr, error) {
+        if self.annotate_mut_binding_to_immutable_binding(err, expr, expr_ty, expected, error) {
             return;
         }
 
@@ -799,17 +799,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Detect the following case
     ///
     /// ```text
-    /// fn change_object(mut a: &Ty) {
+    /// fn change_object(mut b: &Ty) {
     ///     let a = Ty::new();
     ///     b = a;
     /// }
     /// ```
     ///
-    /// where the user likely meant to modify the value behind there reference, use `a` as an out
+    /// where the user likely meant to modify the value behind there reference, use `b` as an out
     /// parameter, instead of mutating the local binding. When encountering this we suggest:
     ///
     /// ```text
-    /// fn change_object(a: &'_ mut Ty) {
+    /// fn change_object(b: &'_ mut Ty) {
     ///     let a = Ty::new();
     ///     *b = a;
     /// }
@@ -818,13 +818,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'_>,
+        expr_ty: Ty<'tcx>,
+        expected: Ty<'tcx>,
         error: Option<TypeError<'tcx>>,
     ) -> bool {
-        if let Some(TypeError::Sorts(ExpectedFound { expected, found })) = error
+        if let Some(TypeError::Sorts(ExpectedFound { .. })) = error
             && let ty::Ref(_, inner, hir::Mutability::Not) = expected.kind()
 
             // The difference between the expected and found values is one level of borrowing.
-            && self.can_eq(self.param_env, *inner, found)
+            && self.can_eq(self.param_env, *inner, expr_ty)
 
             // We have an `ident = expr;` assignment.
             && let hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Assign(lhs, rhs, _), .. }) =
diff --git a/compiler/rustc_hir_typeck/src/gather_locals.rs b/compiler/rustc_hir_typeck/src/gather_locals.rs
index 956671fc66e..7d99b0e7869 100644
--- a/compiler/rustc_hir_typeck/src/gather_locals.rs
+++ b/compiler/rustc_hir_typeck/src/gather_locals.rs
@@ -218,7 +218,12 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
             );
         }
         let old_outermost_fn_param_pat = self.outermost_fn_param_pat.take();
-        intravisit::walk_pat(self, p);
+        if let PatKind::Guard(subpat, _) = p.kind {
+            // We'll visit the guard when checking it. Don't gather its locals twice.
+            self.visit_pat(subpat);
+        } else {
+            intravisit::walk_pat(self, p);
+        }
         self.outermost_fn_param_pat = old_outermost_fn_param_pat;
     }
 
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 9be041f75d7..b2497cb0de1 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -9,17 +9,21 @@
 //! which creates a new `TypeckResults` which doesn't contain any inference variables.
 
 use std::mem;
+use std::ops::ControlFlow;
 
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_data_structures::unord::ExtendUnord;
-use rustc_errors::ErrorGuaranteed;
+use rustc_errors::{E0720, ErrorGuaranteed};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, InferKind, Visitor};
 use rustc_hir::{self as hir, AmbigArg, HirId};
 use rustc_infer::traits::solve::Goal;
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCoercion};
 use rustc_middle::ty::{
-    self, DefiningScopeKind, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable,
-    TypeVisitableExt, fold_regions,
+    self, DefiningScopeKind, OpaqueHiddenType, Ty, TyCtxt, TypeFoldable, TypeFolder,
+    TypeSuperFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
+    fold_regions,
 };
 use rustc_span::{Span, sym};
 use rustc_trait_selection::error_reporting::infer::need_type_info::TypeAnnotationNeeded;
@@ -595,6 +599,35 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
                 entry.span = prev.span.substitute_dummy(hidden_type.span);
             }
         }
+
+        let recursive_opaques: Vec<_> = self
+            .typeck_results
+            .concrete_opaque_types
+            .iter()
+            .filter(|&(&def_id, hidden_ty)| {
+                hidden_ty
+                    .ty
+                    .visit_with(&mut HasRecursiveOpaque {
+                        def_id,
+                        seen: Default::default(),
+                        opaques: &self.typeck_results.concrete_opaque_types,
+                        tcx,
+                    })
+                    .is_break()
+            })
+            .map(|(def_id, hidden_ty)| (*def_id, hidden_ty.span))
+            .collect();
+        for (def_id, span) in recursive_opaques {
+            let guar = self
+                .fcx
+                .dcx()
+                .struct_span_err(span, "cannot resolve opaque type")
+                .with_code(E0720)
+                .emit();
+            self.typeck_results
+                .concrete_opaque_types
+                .insert(def_id, OpaqueHiddenType { span, ty: Ty::new_error(tcx, guar) });
+        }
     }
 
     fn visit_field_id(&mut self, hir_id: HirId) {
@@ -959,3 +992,34 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for EagerlyNormalizeConsts<'tcx> {
         self.tcx.try_normalize_erasing_regions(self.typing_env, ct).unwrap_or(ct)
     }
 }
+
+struct HasRecursiveOpaque<'a, 'tcx> {
+    def_id: LocalDefId,
+    seen: FxHashSet<LocalDefId>,
+    opaques: &'a FxIndexMap<LocalDefId, ty::OpaqueHiddenType<'tcx>>,
+    tcx: TyCtxt<'tcx>,
+}
+
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for HasRecursiveOpaque<'_, 'tcx> {
+    type Result = ControlFlow<()>;
+
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
+        if let ty::Alias(ty::Opaque, alias_ty) = *t.kind()
+            && let Some(def_id) = alias_ty.def_id.as_local()
+        {
+            if self.def_id == def_id {
+                return ControlFlow::Break(());
+            }
+
+            if self.seen.insert(def_id)
+                && let Some(hidden_ty) = self.opaques.get(&def_id)
+            {
+                ty::EarlyBinder::bind(hidden_ty.ty)
+                    .instantiate(self.tcx, alias_ty.args)
+                    .visit_with(self)?;
+            }
+        }
+
+        t.super_visit_with(self)
+    }
+}
diff --git a/compiler/rustc_metadata/messages.ftl b/compiler/rustc_metadata/messages.ftl
index cac8f34b0fa..bccffe39243 100644
--- a/compiler/rustc_metadata/messages.ftl
+++ b/compiler/rustc_metadata/messages.ftl
@@ -2,7 +2,7 @@ metadata_as_needed_compatibility =
     linking modifier `as-needed` is only compatible with `dylib` and `framework` linking kinds
 
 metadata_async_drop_types_in_dependency =
-    found async drop types in dependecy `{$extern_crate}`, but async_drop feature is disabled for `{$local_crate}`
+    found async drop types in dependency `{$extern_crate}`, but async_drop feature is disabled for `{$local_crate}`
     .help = if async drop type will be dropped in a crate without `feature(async_drop)`, sync Drop will be used
 
 metadata_bad_panic_strategy =
diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs
index a89d01dcbbe..d9f1888bfd9 100644
--- a/compiler/rustc_pattern_analysis/src/rustc.rs
+++ b/compiler/rustc_pattern_analysis/src/rustc.rs
@@ -1,6 +1,5 @@
 use std::fmt;
 use std::iter::once;
-use std::ops::ControlFlow;
 
 use rustc_abi::{FIRST_VARIANT, FieldIdx, Integer, VariantIdx};
 use rustc_arena::DroplessArena;
@@ -12,8 +11,7 @@ use rustc_middle::mir::{self, Const};
 use rustc_middle::thir::{self, Pat, PatKind, PatRange, PatRangeBoundary};
 use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::ty::{
-    self, FieldDef, OpaqueTypeKey, ScalarInt, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
-    TypeVisitableExt, TypeVisitor, VariantDef,
+    self, FieldDef, OpaqueTypeKey, ScalarInt, Ty, TyCtxt, TypeVisitableExt, VariantDef,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint;
@@ -137,22 +135,11 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
     /// Returns the hidden type corresponding to this key if the body under analysis is allowed to
     /// know it.
     fn reveal_opaque_key(&self, key: OpaqueTypeKey<'tcx>) -> Option<Ty<'tcx>> {
-        if let Some(hidden_ty) = self.typeck_results.concrete_opaque_types.get(&key.def_id) {
-            let ty = ty::EarlyBinder::bind(hidden_ty.ty).instantiate(self.tcx, key.args);
-            if ty.visit_with(&mut RecursiveOpaque { def_id: key.def_id.into() }).is_continue() {
-                Some(ty)
-            } else {
-                // HACK: We skip revealing opaque types which recursively expand
-                // to themselves. This is because we may infer hidden types like
-                // `Opaque<T> = Opaque<Opaque<T>>` or `Opaque<T> = Opaque<(T,)>`
-                // in hir typeck.
-                None
-            }
-        } else {
-            None
-        }
+        self.typeck_results
+            .concrete_opaque_types
+            .get(&key.def_id)
+            .map(|x| ty::EarlyBinder::bind(x.ty).instantiate(self.tcx, key.args))
     }
-
     // This can take a non-revealed `Ty` because it reveals opaques itself.
     pub fn is_uninhabited(&self, ty: Ty<'tcx>) -> bool {
         !ty.inhabited_predicate(self.tcx).apply_revealing_opaque(
@@ -1177,20 +1164,3 @@ fn detect_mixed_deref_pat_ctors<'p, 'tcx>(
     }
     Ok(())
 }
-
-struct RecursiveOpaque {
-    def_id: DefId,
-}
-impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for RecursiveOpaque {
-    type Result = ControlFlow<()>;
-
-    fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
-        if let ty::Alias(ty::Opaque, alias_ty) = t.kind() {
-            if alias_ty.def_id == self.def_id {
-                return ControlFlow::Break(());
-            }
-        }
-
-        if t.has_opaque_types() { t.super_visit_with(self) } else { ControlFlow::Continue(()) }
-    }
-}
diff --git a/compiler/rustc_type_ir/src/region_kind.rs b/compiler/rustc_type_ir/src/region_kind.rs
index eae3213ead0..1b5d04e6025 100644
--- a/compiler/rustc_type_ir/src/region_kind.rs
+++ b/compiler/rustc_type_ir/src/region_kind.rs
@@ -193,7 +193,7 @@ impl<I: Interner> fmt::Debug for RegionKind<I> {
 
             ReVar(vid) => write!(f, "{vid:?}"),
 
-            RePlaceholder(placeholder) => write!(f, "{placeholder:?}"),
+            RePlaceholder(placeholder) => write!(f, "'{placeholder:?}"),
 
             // Use `'{erased}` as the output instead of `'erased` so that its more obviously distinct from
             // a `ReEarlyParam` named `'erased`. Technically that would print as `'erased/#IDX` so this is