Auto merge of #120951 - matthiaskrgr:rollup-0nnm7dv, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #110483 (Create try_new function for ThinBox)
 - #120740 (Make cmath.rs a single file)
 - #120872 (hir: Refactor getters for HIR parents)
 - #120880 (add note on comparing vtables / function pointers)
 - #120885 (interpret/visitor: ensure we only see normalized types)
 - #120888 (assert_unsafe_precondition cleanup)
 - #120897 (Encode `coroutine_for_closure` for foreign crates)
 - #120937 ([docs] Update armv6k-nintendo-3ds platform docs for outdated info)

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

2 files changed, 40 insertions, 51 deletions

diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index bf72aac1033..50817dd0a80 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -82,7 +82,7 @@ impl<'hir> Iterator for ParentHirIterator<'hir> {
         }
 
         // There are nodes that do not have entries, so we need to skip them.
-        let parent_id = self.map.parent_id(self.current_id);
+        let parent_id = self.map.tcx.parent_hir_id(self.current_id);
 
         if parent_id == self.current_id {
             self.current_id = CRATE_HIR_ID;
@@ -175,6 +175,28 @@ impl<'tcx> TyCtxt<'tcx> {
         self.opt_hir_node_by_def_id(id)
             .unwrap_or_else(|| bug!("couldn't find HIR node for def id {id:?}"))
     }
+
+    /// Returns `HirId` of the parent HIR node of node with this `hir_id`.
+    /// Returns the same `hir_id` if and only if `hir_id == CRATE_HIR_ID`.
+    ///
+    /// If calling repeatedly and iterating over parents, prefer [`Map::parent_iter`].
+    pub fn parent_hir_id(self, hir_id: HirId) -> HirId {
+        let HirId { owner, local_id } = hir_id;
+        if local_id == ItemLocalId::from_u32(0) {
+            self.hir_owner_parent(owner)
+        } else {
+            let parent_local_id = self.hir_owner_nodes(owner).nodes[local_id].parent;
+            // HIR indexing should have checked that.
+            debug_assert_ne!(parent_local_id, local_id);
+            HirId { owner, local_id: parent_local_id }
+        }
+    }
+
+    /// Returns parent HIR node of node with this `hir_id`.
+    /// Returns HIR node of the same `hir_id` if and only if `hir_id == CRATE_HIR_ID`.
+    pub fn parent_hir_node(self, hir_id: HirId) -> Node<'tcx> {
+        self.hir_node(self.parent_hir_id(hir_id))
+    }
 }
 
 impl<'hir> Map<'hir> {
@@ -217,39 +239,6 @@ impl<'hir> Map<'hir> {
         self.tcx.definitions_untracked().def_path_hash(def_id)
     }
 
-    /// Finds the id of the parent node to this one.
-    ///
-    /// If calling repeatedly and iterating over parents, prefer [`Map::parent_iter`].
-    pub fn opt_parent_id(self, id: HirId) -> Option<HirId> {
-        if id.local_id == ItemLocalId::from_u32(0) {
-            // FIXME: This function never returns `None` right now, and the parent chain end is
-            // determined by checking for `parent(id) == id`. This function should return `None`
-            // for the crate root instead.
-            Some(self.tcx.hir_owner_parent(id.owner))
-        } else {
-            let owner = self.tcx.hir_owner_nodes(id.owner);
-            let node = &owner.nodes[id.local_id];
-            let hir_id = HirId { owner: id.owner, local_id: node.parent };
-            // HIR indexing should have checked that.
-            debug_assert_ne!(id.local_id, node.parent);
-            Some(hir_id)
-        }
-    }
-
-    #[track_caller]
-    pub fn parent_id(self, hir_id: HirId) -> HirId {
-        self.opt_parent_id(hir_id)
-            .unwrap_or_else(|| bug!("No parent for node {}", self.node_to_string(hir_id)))
-    }
-
-    pub fn get_parent(self, hir_id: HirId) -> Node<'hir> {
-        self.tcx.hir_node(self.parent_id(hir_id))
-    }
-
-    pub fn find_parent(self, hir_id: HirId) -> Option<Node<'hir>> {
-        Some(self.tcx.hir_node(self.opt_parent_id(hir_id)?))
-    }
-
     pub fn get_if_local(self, id: DefId) -> Option<Node<'hir>> {
         id.as_local()
             .and_then(|id| Some(self.tcx.hir_node(self.tcx.opt_local_def_id_to_hir_id(id)?)))
@@ -304,14 +293,13 @@ impl<'hir> Map<'hir> {
     /// which this is the body of, i.e., a `fn`, `const` or `static`
     /// item (possibly associated), a closure, or a `hir::AnonConst`.
     pub fn body_owner(self, BodyId { hir_id }: BodyId) -> HirId {
-        let parent = self.parent_id(hir_id);
+        let parent = self.tcx.parent_hir_id(hir_id);
         assert!(is_body_owner(self.tcx.hir_node(parent), hir_id), "{hir_id:?}");
         parent
     }
 
     pub fn body_owner_def_id(self, BodyId { hir_id }: BodyId) -> LocalDefId {
-        let parent = self.parent_id(hir_id);
-        associated_body(self.tcx.hir_node(parent)).unwrap().0
+        associated_body(self.tcx.parent_hir_node(hir_id)).unwrap().0
     }
 
     /// Given a `LocalDefId`, returns the `BodyId` associated with it,
@@ -569,8 +557,8 @@ impl<'hir> Map<'hir> {
 
     /// Checks if the node is left-hand side of an assignment.
     pub fn is_lhs(self, id: HirId) -> bool {
-        match self.find_parent(id) {
-            Some(Node::Expr(expr)) => match expr.kind {
+        match self.tcx.parent_hir_node(id) {
+            Node::Expr(expr) => match expr.kind {
                 ExprKind::Assign(lhs, _rhs, _span) => lhs.hir_id == id,
                 _ => false,
             },
@@ -793,7 +781,7 @@ impl<'hir> Map<'hir> {
             Node::Pat(&Pat { kind: PatKind::Binding(_, _, ident, _), .. }) => Some(ident),
             // A `Ctor` doesn't have an identifier itself, but its parent
             // struct/variant does. Compare with `hir::Map::span`.
-            Node::Ctor(..) => match self.find_parent(id)? {
+            Node::Ctor(..) => match self.tcx.parent_hir_node(id) {
                 Node::Item(item) => Some(item.ident),
                 Node::Variant(variant) => Some(variant.ident),
                 _ => unreachable!(),
@@ -925,7 +913,7 @@ impl<'hir> Map<'hir> {
                 ForeignItemKind::Fn(decl, _, _) => until_within(item.span, decl.output.span()),
                 _ => named_span(item.span, item.ident, None),
             },
-            Node::Ctor(_) => return self.span(self.parent_id(hir_id)),
+            Node::Ctor(_) => return self.span(self.tcx.parent_hir_id(hir_id)),
             Node::Expr(Expr {
                 kind: ExprKind::Closure(Closure { fn_decl_span, .. }),
                 span,
@@ -968,7 +956,7 @@ impl<'hir> Map<'hir> {
             Node::PatField(field) => field.span,
             Node::Arm(arm) => arm.span,
             Node::Block(block) => block.span,
-            Node::Ctor(..) => self.span_with_body(self.parent_id(hir_id)),
+            Node::Ctor(..) => self.span_with_body(self.tcx.parent_hir_id(hir_id)),
             Node::Lifetime(lifetime) => lifetime.ident.span,
             Node::GenericParam(param) => param.span,
             Node::Infer(i) => i.span,
@@ -1001,7 +989,7 @@ impl<'hir> Map<'hir> {
     /// Returns the HirId of `N` in `struct Foo<const N: usize = { ... }>` when
     /// called with the HirId for the `{ ... }` anon const
     pub fn opt_const_param_default_param_def_id(self, anon_const: HirId) -> Option<LocalDefId> {
-        match self.get_parent(anon_const) {
+        match self.tcx.parent_hir_node(anon_const) {
             Node::GenericParam(GenericParam {
                 def_id: param_id,
                 kind: GenericParamKind::Const { .. },
@@ -1026,7 +1014,7 @@ impl<'hir> Map<'hir> {
             _ => None,
         }?;
 
-        match self.find_parent(expr.hir_id)? {
+        match self.tcx.parent_hir_node(expr.hir_id) {
             Node::ExprField(field) => {
                 if field.ident.name == local.name && field.is_shorthand {
                     return Some(local.name);
diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index f66cd2370e3..4ef9bc16221 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -136,13 +136,14 @@ pub fn provide(providers: &mut Providers) {
     };
     providers.opt_hir_owner_nodes =
         |tcx, id| tcx.hir_crate(()).owners.get(id)?.as_owner().map(|i| &i.nodes);
-    providers.hir_owner_parent = |tcx, id| {
-        // Accessing the local_parent is ok since its value is hashed as part of `id`'s DefPathHash.
-        tcx.opt_local_parent(id.def_id).map_or(CRATE_HIR_ID, |parent| {
-            let mut parent_hir_id = tcx.local_def_id_to_hir_id(parent);
-            parent_hir_id.local_id =
-                tcx.hir_crate(()).owners[parent_hir_id.owner.def_id].unwrap().parenting[&id.def_id];
-            parent_hir_id
+    providers.hir_owner_parent = |tcx, owner_id| {
+        tcx.opt_local_parent(owner_id.def_id).map_or(CRATE_HIR_ID, |parent_def_id| {
+            let parent_owner_id = tcx.local_def_id_to_hir_id(parent_def_id).owner;
+            HirId {
+                owner: parent_owner_id,
+                local_id: tcx.hir_crate(()).owners[parent_owner_id.def_id].unwrap().parenting
+                    [&owner_id.def_id],
+            }
         })
     };
     providers.hir_attrs = |tcx, id| {