1 files changed, 27 insertions, 7 deletions
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 9ba70abd4d9..05bc3611dd8 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -1139,7 +1139,7 @@ pub struct Resolver<'ra, 'tcx> {
     proc_macro_stubs: FxHashSet<LocalDefId>,
     /// Traces collected during macro resolution and validated when it's complete.
     single_segment_macro_resolutions:
-        Vec<(Ident, MacroKind, ParentScope<'ra>, Option<NameBinding<'ra>>)>,
+        Vec<(Ident, MacroKind, ParentScope<'ra>, Option<NameBinding<'ra>>, Option<Span>)>,
     multi_segment_macro_resolutions:
         Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'ra>, Option<Res>, Namespace)>,
     builtin_attrs: Vec<(Ident, ParentScope<'ra>)>,
@@ -1224,6 +1224,11 @@ pub struct Resolver<'ra, 'tcx> {
     current_crate_outer_attr_insert_span: Span,
 
     mods_with_parse_errors: FxHashSet<DefId>,
+
+    // Stores pre-expansion and pre-placeholder-fragment-insertion names for `impl Trait` types
+    // that were encountered during resolution. These names are used to generate item names
+    // for APITs, so we don't want to leak details of resolution into these names.
+    impl_trait_names: FxHashMap<NodeId, Symbol>,
 }
 
 /// This provides memory for the rest of the crate. The `'ra` lifetime that is
@@ -1579,6 +1584,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             impl_binding_keys: Default::default(),
             current_crate_outer_attr_insert_span,
             mods_with_parse_errors: Default::default(),
+            impl_trait_names: Default::default(),
         };
 
         let root_parent_scope = ParentScope::module(graph_root, &resolver);
@@ -1934,12 +1940,26 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         }
         if let NameBindingKind::Import { import, binding } = used_binding.kind {
             if let ImportKind::MacroUse { warn_private: true } = import.kind {
-                self.lint_buffer().buffer_lint(
-                    PRIVATE_MACRO_USE,
-                    import.root_id,
-                    ident.span,
-                    BuiltinLintDiag::MacroIsPrivate(ident),
-                );
+                // Do not report the lint if the macro name resolves in stdlib prelude
+                // even without the problematic `macro_use` import.
+                let found_in_stdlib_prelude = self.prelude.is_some_and(|prelude| {
+                    self.maybe_resolve_ident_in_module(
+                        ModuleOrUniformRoot::Module(prelude),
+                        ident,
+                        MacroNS,
+                        &ParentScope::module(self.empty_module, self),
+                        None,
+                    )
+                    .is_ok()
+                });
+                if !found_in_stdlib_prelude {
+                    self.lint_buffer().buffer_lint(
+                        PRIVATE_MACRO_USE,
+                        import.root_id,
+                        ident.span,
+                        BuiltinLintDiag::MacroIsPrivate(ident),
+                    );
+                }
             }
             // Avoid marking `extern crate` items that refer to a name from extern prelude,
             // but not introduce it, as used if they are accessed from lexical scope.