Rollup merge of #141831 - lolbinarycat:rustdoc-extern-reexport-135092, r=GuillaumeGomez

rustdoc: fix attrs of locally reexported foreign items

fixes rust-lang/rust#135092

also tweaks a few outdated/misleading comments.

r? `@GuillaumeGomez`

src/librustdoc/clean/mod.rs

@@ -66,8 +66,8 @@ use crate::visit_ast::Module as DocModule;
 pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
     let mut items: Vec<Item> = vec![];
     let mut inserted = FxHashSet::default();
-    items.extend(doc.foreigns.iter().map(|(item, renamed)| {
-        let item = clean_maybe_renamed_foreign_item(cx, item, *renamed);
+    items.extend(doc.foreigns.iter().map(|(item, renamed, import_id)| {
+        let item = clean_maybe_renamed_foreign_item(cx, item, *renamed, *import_id);
         if let Some(name) = item.name
             && (cx.render_options.document_hidden || !item.is_doc_hidden())
         {
@@ -89,7 +89,7 @@ pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<
         Some(item)
     }));
 
-    // Split up imports from all other items.
+    // Split up glob imports from all other items.
     //
     // This covers the case where somebody does an import which should pull in an item,
     // but there's already an item with the same namespace and same name. Rust gives
@@ -2762,7 +2762,6 @@ fn clean_maybe_renamed_item<'tcx>(
     import_id: Option<LocalDefId>,
 ) -> Vec<Item> {
     use hir::ItemKind;
-
     fn get_name(
         cx: &DocContext<'_>,
         item: &hir::Item<'_>,
@@ -2974,6 +2973,7 @@ fn clean_extern_crate<'tcx>(
         && !cx.is_json_output();
 
     let krate_owner_def_id = krate.owner_id.def_id;
+
     if please_inline
         && let Some(items) = inline::try_inline(
             cx,
@@ -3135,6 +3135,7 @@ fn clean_maybe_renamed_foreign_item<'tcx>(
     cx: &mut DocContext<'tcx>,
     item: &hir::ForeignItem<'tcx>,
     renamed: Option<Symbol>,
+    import_id: Option<LocalDefId>,
 ) -> Item {
     let def_id = item.owner_id.to_def_id();
     cx.with_param_env(def_id, |cx| {
@@ -3150,11 +3151,13 @@ fn clean_maybe_renamed_foreign_item<'tcx>(
             hir::ForeignItemKind::Type => ForeignTypeItem,
         };
 
-        Item::from_def_id_and_parts(
-            item.owner_id.def_id.to_def_id(),
-            Some(renamed.unwrap_or(item.ident.name)),
-            kind,
+        generate_item_with_correct_attrs(
             cx,
+            kind,
+            item.owner_id.def_id.to_def_id(),
+            item.ident.name,
+            import_id,
+            renamed,
         )
     })
 }

src/librustdoc/visit_ast.rs

@@ -38,9 +38,18 @@ pub(crate) struct Module<'hir> {
         (LocalDefId, Option<Symbol>),
         (&'hir hir::Item<'hir>, Option<Symbol>, Option<LocalDefId>),
     >,
-    /// Same as for `items`.
+
+    /// (def_id, renamed) -> (res, local_import_id)
+    ///
+    /// `inlined_foreigns` only contains `extern` items
+    /// that are cross-crate inlined.
+    ///
+    /// Locally inlined `extern` items are
+    /// stored in `foreigns` with the `import_id` set,
+    /// analogous to how `items` is.
     pub(crate) inlined_foreigns: FxIndexMap<(DefId, Option<Symbol>), (Res, LocalDefId)>,
-    pub(crate) foreigns: Vec<(&'hir hir::ForeignItem<'hir>, Option<Symbol>)>,
+    /// (item, renamed, import_id)
+    pub(crate) foreigns: Vec<(&'hir hir::ForeignItem<'hir>, Option<Symbol>, Option<LocalDefId>)>,
 }
 
 impl Module<'_> {
@@ -327,7 +336,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             }
             Node::ForeignItem(it) if !glob => {
                 let prev = mem::replace(&mut self.inlining, true);
-                self.visit_foreign_item_inner(it, renamed);
+                self.visit_foreign_item_inner(it, renamed, Some(def_id));
                 self.inlining = prev;
                 true
             }
@@ -432,7 +441,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             hir::ItemKind::ForeignMod { items, .. } => {
                 for item in items {
                     let item = tcx.hir_foreign_item(item.id);
-                    self.visit_foreign_item_inner(item, None);
+                    self.visit_foreign_item_inner(item, None, None);
                 }
             }
             // If we're inlining, skip private items.
@@ -527,10 +536,11 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         &mut self,
         item: &'tcx hir::ForeignItem<'_>,
         renamed: Option<Symbol>,
+        import_id: Option<LocalDefId>,
     ) {
         // If inlining we only want to include public functions.
         if !self.inlining || self.cx.tcx.visibility(item.owner_id).is_public() {
-            self.modules.last_mut().unwrap().foreigns.push((item, renamed));
+            self.modules.last_mut().unwrap().foreigns.push((item, renamed, import_id));
         }
     }
 

tests/rustdoc/reexport/extern-135092.rs

@@ -0,0 +1,26 @@
+// Test to make sure reexports of extern items are combined
+// <https://github.com/rust-lang/rust/issues/135092>
+
+#![crate_name = "foo"]
+
+mod native {
+    extern "C" {
+        /// bar.
+        pub fn bar();
+    }
+
+    /// baz.
+    pub fn baz() {}
+}
+
+//@ has 'foo/fn.bar.html'
+//@ has - '//div[@class="docblock"]' 'bar.'
+//@ has - '//div[@class="docblock"]' 'foo'
+/// foo
+pub use native::bar;
+
+//@ has 'foo/fn.baz.html'
+//@ has - '//div[@class="docblock"]' 'baz.'
+//@ has - '//div[@class="docblock"]' 'foo'
+/// foo
+pub use native::baz;