From fd701b79a71a93a4df5f60262e249e23aa1648cb Mon Sep 17 00:00:00 2001
From: Oli Scherer <rust@oli-obk.de>
Date: Mon, 4 May 2026 10:37:46 +0200
Subject: [PATCH] Remove most uses of `def_id_to_node_id`

Especially those happening during normal resolving, where we are actually looking at current parent scopes
---
 compiler/rustc_resolve/src/diagnostics.rs | 15 ++++++++-------
 compiler/rustc_resolve/src/late.rs        |  8 ++++----
 compiler/rustc_resolve/src/lib.rs         |  4 ++--
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index f891622d0bae..c082455380ce 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -5,7 +5,8 @@ use std::ops::ControlFlow;
 use itertools::Itertools as _;
 use rustc_ast::visit::{self, Visitor};
 use rustc_ast::{
-    self as ast, CRATE_NODE_ID, Crate, ItemKind, ModKind, NodeId, Path, join_path_idents,
+    self as ast, CRATE_NODE_ID, Crate, DUMMY_NODE_ID, ItemKind, ModKind, NodeId, Path,
+    join_path_idents,
 };
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -192,11 +193,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     fn report_with_use_injections(&mut self, krate: &Crate) {
-        for UseError { mut err, candidates, def_id, instead, suggestion, path, is_call } in
+        for UseError { mut err, candidates, node_id, instead, suggestion, path, is_call } in
             mem::take(&mut self.use_injections)
         {
-            let (span, found_use) = if let Some(def_id) = def_id.as_local() {
-                UsePlacementFinder::check(krate, self.def_id_to_node_id(def_id))
+            let (span, found_use) = if node_id != DUMMY_NODE_ID {
+                UsePlacementFinder::check(krate, node_id)
             } else {
                 (None, FoundUse::No)
             };
@@ -1705,9 +1706,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
         let import_suggestions =
             self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, is_expected);
-        let (span, found_use) = match parent_scope.module.nearest_parent_mod().as_local() {
-            Some(def_id) => UsePlacementFinder::check(krate, self.def_id_to_node_id(def_id)),
-            None => (None, FoundUse::No),
+        let (span, found_use) = match parent_scope.module.nearest_parent_mod_node_id() {
+            DUMMY_NODE_ID => (None, FoundUse::No),
+            node_id => UsePlacementFinder::check(krate, node_id),
         };
         show_candidates(
             self.tcx,
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 29a151b277d5..3337a4626b04 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -4515,7 +4515,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                     parent_qself,
                 );
 
-                let def_id = this.parent_scope.module.nearest_parent_mod();
+                let node_id = this.parent_scope.module.nearest_parent_mod_node_id();
                 let instead = res.is_some();
                 let (suggestion, const_err) = if let Some((start, end)) =
                     this.diag_metadata.in_range
@@ -4557,7 +4557,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 let ue = UseError {
                     err,
                     candidates,
-                    def_id,
+                    node_id,
                     instead,
                     suggestion,
                     path: path.into(),
@@ -4646,7 +4646,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 
                 parent_err.cancel();
 
-                let def_id = this.parent_scope.module.nearest_parent_mod();
+                let node_id = this.parent_scope.module.nearest_parent_mod_node_id();
 
                 if this.should_report_errs() {
                     if candidates.is_empty() {
@@ -4671,7 +4671,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                         this.r.use_injections.push(UseError {
                             err,
                             candidates,
-                            def_id,
+                            node_id,
                             instead: false,
                             suggestion: None,
                             path: prefix_path.into(),
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index af9a72b13c1d..f5f063ecaf45 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -1001,8 +1001,8 @@ struct UseError<'a> {
     err: Diag<'a>,
     /// Candidates which user could `use` to access the missing type.
     candidates: Vec<ImportSuggestion>,
-    /// The `DefId` of the module to place the use-statements in.
-    def_id: DefId,
+    /// The `NodeId` of the module to place the use-statements in.
+    node_id: NodeId,
     /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
     instead: bool,
     /// Extra free-form suggestion.