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

Rollup of 8 pull requests

Successful merges:

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 - rust-lang#120937 ([docs] Update armv6k-nintendo-3ds platform docs for outdated info)

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

Author: bors

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -403,8 +403,7 @@ 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);
-                let parent = self.infcx.tcx.hir_node(hir_id);
+                let parent = self.infcx.tcx.parent_hir_node(expr.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)
@@ -1660,8 +1659,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         // Check that the parent of the closure is a method call,
         // with receiver matching with local's type (modulo refs)
-        let parent = hir.parent_id(closure_expr.hir_id);
-        if let hir::Node::Expr(parent) = tcx.hir_node(parent) {
+        if let hir::Node::Expr(parent) = tcx.parent_hir_node(closure_expr.hir_id) {
             if let hir::ExprKind::MethodCall(_, recv, ..) = parent.kind {
                 let recv_ty = typeck_results.expr_ty(recv);
 

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -944,7 +944,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let hir = self.infcx.tcx.hir();
         let closure_id = self.mir_hir_id();
         let closure_span = self.infcx.tcx.def_span(self.mir_def_id());
-        let fn_call_id = hir.parent_id(closure_id);
+        let fn_call_id = self.infcx.tcx.parent_hir_id(closure_id);
         let node = self.infcx.tcx.hir_node(fn_call_id);
         let def_id = hir.enclosing_body_owner(fn_call_id);
         let mut look_at_return = true;
@@ -1034,7 +1034,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         if let InstanceDef::Item(def_id) = source.instance
             && let Some(Node::Expr(hir::Expr { hir_id, kind, .. })) = hir.get_if_local(def_id)
             && let ExprKind::Closure(hir::Closure { kind: hir::ClosureKind::Closure, .. }) = kind
-            && let Some(Node::Expr(expr)) = hir.find_parent(*hir_id)
+            && let Node::Expr(expr) = self.infcx.tcx.parent_hir_node(*hir_id)
         {
             let mut cur_expr = expr;
             while let ExprKind::MethodCall(path_segment, recv, _, _) = cur_expr.kind {

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -214,8 +214,11 @@ 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(hir.parent_id(gat_hir_id)).generics()
+                    && let Some(generics_impl) = self
+                        .infcx
+                        .tcx
+                        .parent_hir_node(self.infcx.tcx.parent_hir_id(gat_hir_id))
+                        .generics()
                 {
                     Some((gat_hir_id, generics_impl))
                 } else {

compiler/rustc_const_eval/src/interpret/projection.rs

@@ -149,6 +149,8 @@ where
             "`field` projection called on a slice -- call `index` projection instead"
         );
         let offset = base.layout().fields.offset(field);
+        // Computing the layout does normalization, so we get a normalized type out of this
+        // even if the field type is non-normalized (possible e.g. via associated types).
         let field_layout = base.layout().field(self, field);
 
         // Offset may need adjustment for unsized fields.

compiler/rustc_const_eval/src/interpret/visitor.rs

@@ -153,6 +153,16 @@ pub trait ValueVisitor<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>>: Sized {
                 // We visited all parts of this one.
                 return Ok(());
             }
+
+            // Non-normalized types should never show up here.
+            ty::Param(..)
+            | ty::Alias(..)
+            | ty::Bound(..)
+            | ty::Placeholder(..)
+            | ty::Infer(..)
+            | ty::Error(..) => throw_inval!(TooGeneric),
+
+            // The rest is handled below.
             _ => {}
         };
 

compiler/rustc_const_eval/src/transform/check_consts/mod.rs

@@ -131,11 +131,10 @@ fn is_parent_const_stable_trait(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     let local_def_id = def_id.expect_local();
     let hir_id = tcx.local_def_id_to_hir_id(local_def_id);
 
-    let Some(parent) = tcx.hir().opt_parent_id(hir_id) else { return false };
-
-    if !tcx.is_const_trait_impl_raw(parent.owner.def_id.to_def_id()) {
+    let parent_owner_id = tcx.parent_hir_id(hir_id).owner;
+    if !tcx.is_const_trait_impl_raw(parent_owner_id.to_def_id()) {
         return false;
     }
 
-    tcx.lookup_const_stability(parent.owner).is_some_and(|stab| stab.is_const_stable())
+    tcx.lookup_const_stability(parent_owner_id).is_some_and(|stab| stab.is_const_stable())
 }

compiler/rustc_hir/src/hir.rs

@@ -3508,7 +3508,7 @@ impl<'hir> Node<'hir> {
     /// ```ignore (illustrative)
     /// ctor
     ///     .ctor_hir_id()
-    ///     .and_then(|ctor_id| tcx.hir().find_parent(ctor_id))
+    ///     .map(|ctor_id| tcx.parent_hir_node(ctor_id))
     ///     .and_then(|parent| parent.ident())
     /// ```
     pub fn ident(&self) -> Option<Ident> {

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -2749,14 +2749,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         arg_idx: Option<usize>,
     ) -> Option<Ty<'tcx>> {
         let tcx = self.tcx();
-        let hir = tcx.hir();
-
         let hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), ident, .. }) =
             tcx.hir_node(fn_hir_id)
         else {
             return None;
         };
-        let i = hir.get_parent(fn_hir_id).expect_item().expect_impl();
+        let i = tcx.parent_hir_node(fn_hir_id).expect_item().expect_impl();
 
         let trait_ref =
             self.instantiate_mono_trait_ref(i.of_trait.as_ref()?, self.ast_ty_to_ty(i.self_ty));

compiler/rustc_hir_analysis/src/collect.rs

@@ -224,11 +224,8 @@ pub(crate) fn placeholder_type_error_diag<'tcx>(
             is_fn = true;
 
             // Check if parent is const or static
-            let parent_id = tcx.hir().parent_id(hir_ty.hir_id);
-            let parent_node = tcx.hir_node(parent_id);
-
             is_const_or_static = matches!(
-                parent_node,
+                tcx.parent_hir_node(hir_ty.hir_id),
                 Node::Item(&hir::Item {
                     kind: hir::ItemKind::Const(..) | hir::ItemKind::Static(..),
                     ..
@@ -1085,7 +1082,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<ty::PolyFnSig<
 
         ImplItem(hir::ImplItem { kind: ImplItemKind::Fn(sig, _), generics, .. }) => {
             // Do not try to infer the return type for a impl method coming from a trait
-            if let Item(hir::Item { kind: ItemKind::Impl(i), .. }) = tcx.hir().get_parent(hir_id)
+            if let Item(hir::Item { kind: ItemKind::Impl(i), .. }) = tcx.parent_hir_node(hir_id)
                 && i.of_trait.is_some()
             {
                 icx.astconv().ty_of_fn(

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -51,7 +51,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 // of a const parameter type, e.g. `struct Foo<const N: usize, const M: [u8; N]>` is not allowed.
                 None
             } else if tcx.features().generic_const_exprs {
-                let parent_node = tcx.hir().get_parent(hir_id);
+                let parent_node = tcx.parent_hir_node(hir_id);
                 if let Node::Variant(Variant { disr_expr: Some(constant), .. }) = parent_node
                     && constant.hir_id == hir_id
                 {
@@ -113,7 +113,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                     Some(parent_def_id.to_def_id())
                 }
             } else {
-                let parent_node = tcx.hir().get_parent(hir_id);
+                let parent_node = tcx.parent_hir_node(hir_id);
                 match parent_node {
                     // HACK(eddyb) this provides the correct generics for repeat
                     // expressions' count (i.e. `N` in `[x; N]`), and explicit