Merge from rustc

6 files changed, 52 insertions, 36 deletions

diff --git a/compiler/rustc_ast_lowering/src/delegation.rs b/compiler/rustc_ast_lowering/src/delegation.rs
index 4e1c477a3d7..e26a65c1f29 100644
--- a/compiler/rustc_ast_lowering/src/delegation.rs
+++ b/compiler/rustc_ast_lowering/src/delegation.rs
@@ -29,11 +29,12 @@
 //! item id (`item_id`) in case of impl trait or path resolution id (`path_id`) otherwise.
 //!
 //! Since we do not have a proper way to obtain function type information by path resolution
-//! in AST, we mark each function parameter type as `InferDelegation` and inherit it in `AstConv`.
+//! in AST, we mark each function parameter type as `InferDelegation` and inherit it during
+//! HIR ty lowering.
 //!
 //! Similarly generics, predicates and header are set to the "default" values.
 //! In case of discrepancy with callee function the `NotSupportedDelegation` error will
-//! also be emitted in `AstConv`.
+//! also be emitted during HIR ty lowering.
 
 use crate::{ImplTraitPosition, ResolverAstLoweringExt};
 
@@ -129,7 +130,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ) -> &'hir hir::FnDecl<'hir> {
         let args_count = if let Some(local_sig_id) = sig_id.as_local() {
             // Map may be filled incorrectly due to recursive delegation.
-            // Error will be emmited later in astconv.
+            // Error will be emitted later during HIR ty lowering.
             self.resolver.fn_parameter_counts.get(&local_sig_id).cloned().unwrap_or_default()
         } else {
             self.tcx.fn_arg_names(sig_id).len()
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 41f7418ddde..389cf4e3132 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -157,7 +157,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     hir::ExprKind::AddrOf(*k, *m, ohs)
                 }
                 ExprKind::Let(pat, scrutinee, span, is_recovered) => {
-                    hir::ExprKind::Let(self.arena.alloc(hir::Let {
+                    hir::ExprKind::Let(self.arena.alloc(hir::LetExpr {
                         span: self.lower_span(*span),
                         pat: self.lower_pat(pat),
                         ty: None,
@@ -181,10 +181,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     )
                 }),
                 ExprKind::TryBlock(body) => self.lower_expr_try_block(body),
-                ExprKind::Match(expr, arms) => hir::ExprKind::Match(
+                ExprKind::Match(expr, arms, kind) => hir::ExprKind::Match(
                     self.lower_expr(expr),
                     self.arena.alloc_from_iter(arms.iter().map(|x| self.lower_arm(x))),
-                    hir::MatchSource::Normal,
+                    match kind {
+                        MatchKind::Prefix => hir::MatchSource::Normal,
+                        MatchKind::Postfix => hir::MatchSource::Postfix,
+                    },
                 ),
                 ExprKind::Await(expr, await_kw_span) => self.lower_expr_await(*await_kw_span, expr),
                 ExprKind::Closure(box Closure {
diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index 793fe9cfd5e..9078b1f889c 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -55,7 +55,7 @@ pub(super) fn index_hir<'hir>(
         OwnerNode::TraitItem(item) => collector.visit_trait_item(item),
         OwnerNode::ImplItem(item) => collector.visit_impl_item(item),
         OwnerNode::ForeignItem(item) => collector.visit_foreign_item(item),
-        OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+        OwnerNode::Synthetic => unreachable!(),
     };
 
     for (local_id, node) in collector.nodes.iter_enumerated() {
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index 2d03c854bd0..c9786328565 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -1427,8 +1427,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // Error if `?Trait` bounds in where clauses don't refer directly to type parameters.
         // Note: we used to clone these bounds directly onto the type parameter (and avoid lowering
         // these into hir when we lower thee where clauses), but this makes it quite difficult to
-        // keep track of the Span info. Now, `add_implicitly_sized` in `AstConv` checks both param bounds and
-        // where clauses for `?Sized`.
+        // keep track of the Span info. Now, `<dyn HirTyLowerer>::add_implicit_sized_bound`
+        // checks both param bounds and where clauses for `?Sized`.
         for pred in &generics.where_clause.predicates {
             let WherePredicate::BoundPredicate(bound_pred) = pred else {
                 continue;
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 6a7ee936f66..d2744e8ff68 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -55,7 +55,9 @@ use rustc_errors::{DiagArgFromDisplay, DiagCtxt, StashKey};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{LocalDefId, LocalDefIdMap, CRATE_DEF_ID, LOCAL_CRATE};
-use rustc_hir::{ConstArg, GenericArg, ItemLocalMap, ParamName, TraitCandidate};
+use rustc_hir::{
+    ConstArg, GenericArg, ItemLocalMap, MissingLifetimeKind, ParamName, TraitCandidate,
+};
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_macros::extension;
 use rustc_middle::span_bug;
@@ -797,7 +799,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             LifetimeRes::Param { .. } => {
                 (hir::ParamName::Plain(ident), hir::LifetimeParamKind::Explicit)
             }
-            LifetimeRes::Fresh { param, .. } => {
+            LifetimeRes::Fresh { param, kind, .. } => {
                 // Late resolution delegates to us the creation of the `LocalDefId`.
                 let _def_id = self.create_def(
                     self.current_hir_id_owner.def_id,
@@ -808,7 +810,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 );
                 debug!(?_def_id);
 
-                (hir::ParamName::Fresh, hir::LifetimeParamKind::Elided)
+                (hir::ParamName::Fresh, hir::LifetimeParamKind::Elided(kind))
             }
             LifetimeRes::Static | LifetimeRes::Error => return None,
             res => panic!(
@@ -1605,13 +1607,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         for lifetime in captured_lifetimes_to_duplicate {
             let res = self.resolver.get_lifetime_res(lifetime.id).unwrap_or(LifetimeRes::Error);
-            let old_def_id = match res {
-                LifetimeRes::Param { param: old_def_id, binder: _ } => old_def_id,
+            let (old_def_id, missing_kind) = match res {
+                LifetimeRes::Param { param: old_def_id, binder: _ } => (old_def_id, None),
 
-                LifetimeRes::Fresh { param, binder: _ } => {
+                LifetimeRes::Fresh { param, kind, .. } => {
                     debug_assert_eq!(lifetime.ident.name, kw::UnderscoreLifetime);
                     if let Some(old_def_id) = self.orig_opt_local_def_id(param) {
-                        old_def_id
+                        (old_def_id, Some(kind))
                     } else {
                         self.dcx()
                             .span_delayed_bug(lifetime.ident.span, "no def-id for fresh lifetime");
@@ -1651,6 +1653,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     duplicated_lifetime_node_id,
                     duplicated_lifetime_def_id,
                     self.lower_ident(lifetime.ident),
+                    missing_kind,
                 ));
 
                 // Now make an arg that we can use for the generic params of the opaque tykind.
@@ -1668,27 +1671,33 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             let bounds = this
                 .with_remapping(captured_to_synthesized_mapping, |this| lower_item_bounds(this));
 
-            let generic_params = this.arena.alloc_from_iter(
-                synthesized_lifetime_definitions.iter().map(|&(new_node_id, new_def_id, ident)| {
-                    let hir_id = this.lower_node_id(new_node_id);
-                    let (name, kind) = if ident.name == kw::UnderscoreLifetime {
-                        (hir::ParamName::Fresh, hir::LifetimeParamKind::Elided)
-                    } else {
-                        (hir::ParamName::Plain(ident), hir::LifetimeParamKind::Explicit)
-                    };
+            let generic_params =
+                this.arena.alloc_from_iter(synthesized_lifetime_definitions.iter().map(
+                    |&(new_node_id, new_def_id, ident, missing_kind)| {
+                        let hir_id = this.lower_node_id(new_node_id);
+                        let (name, kind) = if ident.name == kw::UnderscoreLifetime {
+                            (
+                                hir::ParamName::Fresh,
+                                hir::LifetimeParamKind::Elided(
+                                    missing_kind.unwrap_or(MissingLifetimeKind::Underscore),
+                                ),
+                            )
+                        } else {
+                            (hir::ParamName::Plain(ident), hir::LifetimeParamKind::Explicit)
+                        };
 
-                    hir::GenericParam {
-                        hir_id,
-                        def_id: new_def_id,
-                        name,
-                        span: ident.span,
-                        pure_wrt_drop: false,
-                        kind: hir::GenericParamKind::Lifetime { kind },
-                        colon_span: None,
-                        source: hir::GenericParamSource::Generics,
-                    }
-                }),
-            );
+                        hir::GenericParam {
+                            hir_id,
+                            def_id: new_def_id,
+                            name,
+                            span: ident.span,
+                            pure_wrt_drop: false,
+                            kind: hir::GenericParamKind::Lifetime { kind },
+                            colon_span: None,
+                            source: hir::GenericParamSource::Generics,
+                        }
+                    },
+                ));
             debug!("lower_async_fn_ret_ty: generic_params={:#?}", generic_params);
 
             let lifetime_mapping = self.arena.alloc_slice(&synthesized_lifetime_args);
diff --git a/compiler/rustc_ast_lowering/src/pat.rs b/compiler/rustc_ast_lowering/src/pat.rs
index 469cdac11e4..8631d90be81 100644
--- a/compiler/rustc_ast_lowering/src/pat.rs
+++ b/compiler/rustc_ast_lowering/src/pat.rs
@@ -91,6 +91,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     PatKind::Box(inner) => {
                         break hir::PatKind::Box(self.lower_pat(inner));
                     }
+                    PatKind::Deref(inner) => {
+                        break hir::PatKind::Deref(self.lower_pat(inner));
+                    }
                     PatKind::Ref(inner, mutbl) => {
                         break hir::PatKind::Ref(self.lower_pat(inner), *mutbl);
                     }