Auto merge of #120709 - matthiaskrgr:rollup-n3yvykf, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - #119614 (unstably allow constants to refer to statics and read from immutable statics)
 - #119939 (Improve 'generic param from outer item' error for `Self` and inside `static`/`const` items)
 - #120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s)
 - #120331 (pattern_analysis: use a plain `Vec` in `DeconstructedPat`)
 - #120396 (Account for unbounded type param receiver in suggestions)
 - #120423 (update indirect structural match lints to match RFC and to show up for dependencies)
 - #120435 (Suggest name value cfg when only value is used for check-cfg)
 - #120502 (Remove `ffi_returns_twice` feature)
 - #120507 (Account for non-overlapping unmet trait bounds in suggestion)
 - #120513 (Normalize type outlives obligations in NLL for new solver)

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

compiler/rustc_ast_lowering/src/index.rs

@@ -15,7 +15,7 @@ struct NodeCollector<'a, 'hir> {
     bodies: &'a SortedMap<ItemLocalId, &'hir Body<'hir>>,
 
     /// Outputs
-    nodes: IndexVec<ItemLocalId, Option<ParentedNode<'hir>>>,
+    nodes: IndexVec<ItemLocalId, ParentedNode<'hir>>,
     parenting: LocalDefIdMap<ItemLocalId>,
 
     /// The parent of this node
@@ -29,16 +29,19 @@ pub(super) fn index_hir<'hir>(
     tcx: TyCtxt<'hir>,
     item: hir::OwnerNode<'hir>,
     bodies: &SortedMap<ItemLocalId, &'hir Body<'hir>>,
-) -> (IndexVec<ItemLocalId, Option<ParentedNode<'hir>>>, LocalDefIdMap<ItemLocalId>) {
-    let mut nodes = IndexVec::new();
+    num_nodes: usize,
+) -> (IndexVec<ItemLocalId, ParentedNode<'hir>>, LocalDefIdMap<ItemLocalId>) {
+    let zero_id = ItemLocalId::new(0);
+    let err_node = ParentedNode { parent: zero_id, node: Node::Err(item.span()) };
+    let mut nodes = IndexVec::from_elem_n(err_node, num_nodes);
     // This node's parent should never be accessed: the owner's parent is computed by the
     // hir_owner_parent query. Make it invalid (= ItemLocalId::MAX) to force an ICE whenever it is
     // used.
-    nodes.push(Some(ParentedNode { parent: ItemLocalId::INVALID, node: item.into() }));
+    nodes[zero_id] = ParentedNode { parent: ItemLocalId::INVALID, node: item.into() };
     let mut collector = NodeCollector {
         tcx,
         owner: item.def_id(),
-        parent_node: ItemLocalId::new(0),
+        parent_node: zero_id,
         nodes,
         bodies,
         parenting: Default::default(),
@@ -54,6 +57,14 @@ pub(super) fn index_hir<'hir>(
         OwnerNode::ForeignItem(item) => collector.visit_foreign_item(item),
     };
 
+    for (local_id, node) in collector.nodes.iter_enumerated() {
+        if let Node::Err(span) = node.node {
+            let hir_id = HirId { owner: item.def_id(), local_id };
+            let msg = format!("ID {hir_id} not encountered when visiting item HIR");
+            tcx.dcx().span_delayed_bug(*span, msg);
+        }
+    }
+
     (collector.nodes, collector.parenting)
 }
 
@@ -88,7 +99,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
             }
         }
 
-        self.nodes.insert(hir_id.local_id, ParentedNode { parent: self.parent_node, node });
+        self.nodes[hir_id.local_id] = ParentedNode { parent: self.parent_node, node };
     }
 
     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_node_id: HirId, f: F) {
@@ -348,4 +359,23 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
 
         self.visit_nested_foreign_item(id);
     }
+
+    fn visit_where_predicate(&mut self, predicate: &'hir WherePredicate<'hir>) {
+        match predicate {
+            WherePredicate::BoundPredicate(pred) => {
+                self.insert(pred.span, pred.hir_id, Node::WhereBoundPredicate(pred));
+                self.with_parent(pred.hir_id, |this| {
+                    intravisit::walk_where_predicate(this, predicate)
+                })
+            }
+            _ => intravisit::walk_where_predicate(self, predicate),
+        }
+    }
+
+    fn visit_array_length(&mut self, len: &'hir ArrayLen) {
+        match len {
+            ArrayLen::Infer(inf) => self.insert(inf.span, inf.hir_id, Node::ArrayLenInfer(inf)),
+            ArrayLen::Body(..) => intravisit::walk_array_len(self, len),
+        }
+    }
 }

compiler/rustc_ast_lowering/src/item.rs

@@ -498,8 +498,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     }
                 }
 
-                let res =
-                    self.expect_full_res_from_use(id).map(|res| self.lower_res(res)).collect();
+                let res = self.lower_import_res(id);
                 let path = self.lower_use_path(res, &path, ParamMode::Explicit);
                 hir::ItemKind::Use(path, hir::UseKind::Single)
             }
@@ -569,8 +568,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     });
                 }
 
-                let res =
-                    self.expect_full_res_from_use(id).map(|res| self.lower_res(res)).collect();
+                let res = self.lower_import_res(id);
                 let path = self.lower_use_path(res, &prefix, ParamMode::Explicit);
                 hir::ItemKind::Use(path, hir::UseKind::ListStem)
             }

compiler/rustc_ast_lowering/src/lib.rs

@@ -64,7 +64,7 @@ use rustc_middle::ty::{ResolverAstLowering, TyCtxt};
 use rustc_session::parse::{add_feature_diagnostics, feature_err};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{DesugaringKind, Span, DUMMY_SP};
-use smallvec::SmallVec;
+use smallvec::{smallvec, SmallVec};
 use std::collections::hash_map::Entry;
 use thin_vec::ThinVec;
 
@@ -675,7 +675,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         } else {
             (None, None)
         };
-        let (nodes, parenting) = index::index_hir(self.tcx, node, &bodies);
+        let num_nodes = self.item_local_id_counter.as_usize();
+        let (nodes, parenting) = index::index_hir(self.tcx, node, &bodies, num_nodes);
         let nodes = hir::OwnerNodes { opt_hash_including_bodies, nodes, bodies };
         let attrs = hir::AttributeMap { map: attrs, opt_hash: attrs_hash };
 
@@ -750,8 +751,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.resolver.get_partial_res(id).map_or(Res::Err, |pr| pr.expect_full_res())
     }
 
-    fn expect_full_res_from_use(&mut self, id: NodeId) -> impl Iterator<Item = Res<NodeId>> {
-        self.resolver.get_import_res(id).present_items()
+    fn lower_import_res(&mut self, id: NodeId) -> SmallVec<[Res; 3]> {
+        let res = self.resolver.get_import_res(id).present_items();
+        let res: SmallVec<_> = res.map(|res| self.lower_res(res)).collect();
+        // FIXME: The `Res::Err` doesn't necessarily mean an error was reported, it also happens
+        // for import list stem items with non-empty list. Instead, consider not emitting such
+        // items into HIR at all, or fill the `import_res_map` tables for them in resolve if that
+        // is not possible. Then add `span_delayed_bug` here.
+        if !res.is_empty() { res } else { smallvec![Res::Err] }
     }
 
     fn make_lang_item_qpath(&mut self, lang_item: hir::LangItem, span: Span) -> hir::QPath<'hir> {

compiler/rustc_ast_lowering/src/path.rs

@@ -196,6 +196,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         p: &Path,
         param_mode: ParamMode,
     ) -> &'hir hir::UsePath<'hir> {
+        assert!((1..=3).contains(&res.len()));
         self.arena.alloc(hir::UsePath {
             res,
             segments: self.arena.alloc_from_iter(p.segments.iter().map(|segment| {

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -401,66 +401,60 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 }
                 let typeck = self.infcx.tcx.typeck(self.mir_def_id());
                 let hir_id = hir.parent_id(expr.hir_id);
-                if let Some(parent) = self.infcx.tcx.opt_hir_node(hir_id) {
-                    let (def_id, args, offset) = if let hir::Node::Expr(parent_expr) = parent
-                        && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
-                        && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
-                    {
-                        (def_id.as_local(), args, 1)
-                    } else if let hir::Node::Expr(parent_expr) = parent
-                        && let hir::ExprKind::Call(call, args) = parent_expr.kind
-                        && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
-                    {
-                        (def_id.as_local(), args, 0)
-                    } else {
-                        (None, &[][..], 0)
+                let parent = self.infcx.tcx.hir_node(hir_id);
+                let (def_id, args, offset) = if let hir::Node::Expr(parent_expr) = parent
+                    && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
+                    && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
+                {
+                    (def_id.as_local(), args, 1)
+                } else if let hir::Node::Expr(parent_expr) = parent
+                    && let hir::ExprKind::Call(call, args) = parent_expr.kind
+                    && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
+                {
+                    (def_id.as_local(), args, 0)
+                } else {
+                    (None, &[][..], 0)
+                };
+                if let Some(def_id) = def_id
+                    && let node =
+                        self.infcx.tcx.hir_node(self.infcx.tcx.local_def_id_to_hir_id(def_id))
+                    && let Some(fn_sig) = node.fn_sig()
+                    && let Some(ident) = node.ident()
+                    && let Some(pos) = args.iter().position(|arg| arg.hir_id == expr.hir_id)
+                    && let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
+                {
+                    let mut span: MultiSpan = arg.span.into();
+                    span.push_span_label(
+                        arg.span,
+                        "this parameter takes ownership of the value".to_string(),
+                    );
+                    let descr = match node.fn_kind() {
+                        Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
+                        Some(hir::intravisit::FnKind::Method(..)) => "method",
+                        Some(hir::intravisit::FnKind::Closure) => "closure",
                     };
-                    if let Some(def_id) = def_id
-                        && let Some(node) = self
-                            .infcx
-                            .tcx
-                            .opt_hir_node(self.infcx.tcx.local_def_id_to_hir_id(def_id))
-                        && let Some(fn_sig) = node.fn_sig()
-                        && let Some(ident) = node.ident()
-                        && let Some(pos) = args.iter().position(|arg| arg.hir_id == expr.hir_id)
-                        && let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
-                    {
-                        let mut span: MultiSpan = arg.span.into();
-                        span.push_span_label(
-                            arg.span,
-                            "this parameter takes ownership of the value".to_string(),
-                        );
-                        let descr = match node.fn_kind() {
-                            Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
-                            Some(hir::intravisit::FnKind::Method(..)) => "method",
-                            Some(hir::intravisit::FnKind::Closure) => "closure",
-                        };
-                        span.push_span_label(ident.span, format!("in this {descr}"));
-                        err.span_note(
-                            span,
-                            format!(
-                                "consider changing this parameter type in {descr} `{ident}` to \
+                    span.push_span_label(ident.span, format!("in this {descr}"));
+                    err.span_note(
+                        span,
+                        format!(
+                            "consider changing this parameter type in {descr} `{ident}` to \
                                  borrow instead if owning the value isn't necessary",
-                            ),
-                        );
-                    }
-                    let place = &self.move_data.move_paths[mpi].place;
-                    let ty = place.ty(self.body, self.infcx.tcx).ty;
-                    if let hir::Node::Expr(parent_expr) = parent
-                        && let hir::ExprKind::Call(call_expr, _) = parent_expr.kind
-                        && let hir::ExprKind::Path(hir::QPath::LangItem(
-                            LangItem::IntoIterIntoIter,
-                            _,
-                        )) = call_expr.kind
-                    {
-                        // Do not suggest `.clone()` in a `for` loop, we already suggest borrowing.
-                    } else if let UseSpans::FnSelfUse { kind: CallKind::Normal { .. }, .. } =
-                        move_spans
-                    {
-                        // We already suggest cloning for these cases in `explain_captures`.
-                    } else {
-                        self.suggest_cloning(err, ty, expr, move_span);
-                    }
+                        ),
+                    );
+                }
+                let place = &self.move_data.move_paths[mpi].place;
+                let ty = place.ty(self.body, self.infcx.tcx).ty;
+                if let hir::Node::Expr(parent_expr) = parent
+                    && let hir::ExprKind::Call(call_expr, _) = parent_expr.kind
+                    && let hir::ExprKind::Path(hir::QPath::LangItem(LangItem::IntoIterIntoIter, _)) =
+                        call_expr.kind
+                {
+                    // Do not suggest `.clone()` in a `for` loop, we already suggest borrowing.
+                } else if let UseSpans::FnSelfUse { kind: CallKind::Normal { .. }, .. } = move_spans
+                {
+                    // We already suggest cloning for these cases in `explain_captures`.
+                } else {
+                    self.suggest_cloning(err, ty, expr, move_span);
                 }
             }
             if let Some(pat) = finder.pat {
@@ -1762,7 +1756,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         fn_decl: hir::FnDecl { inputs, .. },
                         ..
                     }) = e.kind
-                        && let Some(hir::Node::Expr(body)) = self.tcx.opt_hir_node(body.hir_id)
+                        && let hir::Node::Expr(body) = self.tcx.hir_node(body.hir_id)
                     {
                         self.suggest_arg = "this: &Self".to_string();
                         if inputs.len() > 0 {
@@ -1828,11 +1822,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
         }
 
-        if let Some(hir::Node::ImplItem(hir::ImplItem {
+        if let hir::Node::ImplItem(hir::ImplItem {
             kind: hir::ImplItemKind::Fn(_fn_sig, body_id),
             ..
-        })) = self.infcx.tcx.opt_hir_node(self.mir_hir_id())
-            && let Some(hir::Node::Expr(expr)) = self.infcx.tcx.opt_hir_node(body_id.hir_id)
+        }) = self.infcx.tcx.hir_node(self.mir_hir_id())
+            && let hir::Node::Expr(expr) = self.infcx.tcx.hir_node(body_id.hir_id)
         {
             let mut finder = ExpressionFinder {
                 capture_span: *capture_kind_span,
@@ -2400,8 +2394,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 let proper_span = proper_span.source_callsite();
                 if let Some(scope) = self.body.source_scopes.get(source_info.scope)
                     && let ClearCrossCrate::Set(scope_data) = &scope.local_data
-                    && let Some(node) = self.infcx.tcx.opt_hir_node(scope_data.lint_root)
-                    && let Some(id) = node.body_id()
+                    && let Some(id) = self.infcx.tcx.hir_node(scope_data.lint_root).body_id()
                     && let hir::ExprKind::Block(block, _) = self.infcx.tcx.hir().body(id).value.kind
                 {
                     for stmt in block.stmts {

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -87,7 +87,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     if let hir::ExprKind::Path(hir::QPath::Resolved(None, p)) = expr.kind
                         && let [hir::PathSegment { ident, args: None, .. }] = p.segments
                         && let hir::def::Res::Local(hir_id) = p.res
-                        && let Some(hir::Node::Pat(pat)) = tcx.opt_hir_node(hir_id)
+                        && let hir::Node::Pat(pat) = tcx.hir_node(hir_id)
                     {
                         err.span_label(pat.span, format!("binding `{ident}` declared here"));
                     }

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -396,7 +396,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
                 let upvar_hir_id = captured_place.get_root_variable();
 
-                if let Some(Node::Pat(pat)) = self.infcx.tcx.opt_hir_node(upvar_hir_id)
+                if let Node::Pat(pat) = self.infcx.tcx.hir_node(upvar_hir_id)
                     && let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, upvar_ident, _) =
                         pat.kind
                 {
@@ -688,15 +688,15 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                         break;
                     }
                     f_in_trait_opt.and_then(|f_in_trait| {
-                        match self.infcx.tcx.opt_hir_node(f_in_trait) {
-                            Some(Node::TraitItem(hir::TraitItem {
+                        match self.infcx.tcx.hir_node(f_in_trait) {
+                            Node::TraitItem(hir::TraitItem {
                                 kind:
                                     hir::TraitItemKind::Fn(
                                         hir::FnSig { decl: hir::FnDecl { inputs, .. }, .. },
                                         _,
                                     ),
                                 ..
-                            })) => {
+                            }) => {
                                 let hir::Ty { span, .. } = inputs[local.index() - 1];
                                 Some(span)
                             }
@@ -759,10 +759,10 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         //
         // `let &b = a;` -> `let &(mut b) = a;`
         if let Some(hir_id) = hir_id
-            && let Some(hir::Node::Local(hir::Local {
+            && let hir::Node::Local(hir::Local {
                 pat: hir::Pat { kind: hir::PatKind::Ref(_, _), .. },
                 ..
-            })) = self.infcx.tcx.opt_hir_node(hir_id)
+            }) = self.infcx.tcx.hir_node(hir_id)
             && let Ok(name) =
                 self.infcx.tcx.sess.source_map().span_to_snippet(local_decl.source_info.span)
         {
@@ -1206,7 +1206,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 };
 
                 if let Some(hir_id) = hir_id
-                    && let Some(hir::Node::Local(local)) = self.infcx.tcx.opt_hir_node(hir_id)
+                    && let hir::Node::Local(local) = self.infcx.tcx.hir_node(hir_id)
                 {
                     let tables = self.infcx.tcx.typeck(def_id.as_local().unwrap());
                     if let Some(clone_trait) = self.infcx.tcx.lang_items().clone_trait()

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -216,7 +216,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 if let Some(id) = placeholder.bound.kind.get_id()
                     && let Some(placeholder_id) = id.as_local()
                     && let gat_hir_id = self.infcx.tcx.local_def_id_to_hir_id(placeholder_id)
-                    && let Some(generics_impl) = hir.get_parent(gat_hir_id).generics()
+                    && let Some(generics_impl) =
+                        hir.get_parent(hir.parent_id(gat_hir_id)).generics()
                 {
                     Some((gat_hir_id, generics_impl))
                 } else {