Rollup merge of #110450 - GuillaumeGomez:fix-nested-items-on-private-doc, r=notriddle,jyn514

rustdoc: Fix invalid handling of nested items with `--document-private-items`

Fixes #110422.

The problem is that only impl block and re-exported `macro_rules!` items are "visible" as nested items. This PR adds the missing checks to handle this correctly.

cc `@compiler-errors`
r? `@notriddle`

Author: matthiaskrgr

src/librustdoc/visit_ast.rs

@@ -10,6 +10,7 @@ use rustc_hir::{Node, CRATE_HIR_ID};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 
@@ -87,6 +88,7 @@ pub(crate) struct RustdocVisitor<'a, 'tcx> {
     inside_public_path: bool,
     exact_paths: DefIdMap<Vec<Symbol>>,
     modules: Vec<Module<'tcx>>,
+    is_importable_from_parent: bool,
 }
 
 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
@@ -107,6 +109,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             inside_public_path: true,
             exact_paths: Default::default(),
             modules: vec![om],
+            is_importable_from_parent: true,
         }
     }
 
@@ -319,19 +322,31 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         renamed: Option<Symbol>,
         parent_id: Option<LocalDefId>,
     ) {
-        self.modules
-            .last_mut()
-            .unwrap()
-            .items
-            .insert((item.owner_id.def_id, renamed), (item, renamed, parent_id));
+        if self.is_importable_from_parent
+            // If we're inside an item, only impl blocks and `macro_rules!` with the `macro_export`
+            // attribute can still be visible.
+            || match item.kind {
+                hir::ItemKind::Impl(..) => true,
+                hir::ItemKind::Macro(_, MacroKind::Bang) => {
+                    self.cx.tcx.has_attr(item.owner_id.def_id, sym::macro_export)
+                }
+                _ => false,
+            }
+        {
+            self.modules
+                .last_mut()
+                .unwrap()
+                .items
+                .insert((item.owner_id.def_id, renamed), (item, renamed, parent_id));
+        }
     }
 
     fn visit_item_inner(
         &mut self,
         item: &'tcx hir::Item<'_>,
         renamed: Option<Symbol>,
         import_id: Option<LocalDefId>,
-    ) -> bool {
+    ) {
         debug!("visiting item {:?}", item);
         let name = renamed.unwrap_or(item.ident.name);
         let tcx = self.cx.tcx;
@@ -448,7 +463,6 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 }
             }
         }
-        true
     }
 
     fn visit_foreign_item_inner(
@@ -485,9 +499,23 @@ impl<'a, 'tcx> Visitor<'tcx> for RustdocVisitor<'a, 'tcx> {
     }
 
     fn visit_item(&mut self, i: &'tcx hir::Item<'tcx>) {
-        if self.visit_item_inner(i, None, None) {
-            walk_item(self, i);
-        }
+        self.visit_item_inner(i, None, None);
+        let new_value = if self.is_importable_from_parent {
+            matches!(
+                i.kind,
+                hir::ItemKind::Mod(..)
+                    | hir::ItemKind::ForeignMod { .. }
+                    | hir::ItemKind::Impl(..)
+                    | hir::ItemKind::Trait(..)
+            )
+        } else {
+            // Whatever the context, if it's an impl block, the items inside it can be used so they
+            // should be visible.
+            matches!(i.kind, hir::ItemKind::Impl(..))
+        };
+        let prev = mem::replace(&mut self.is_importable_from_parent, new_value);
+        walk_item(self, i);
+        self.is_importable_from_parent = prev;
     }
 
     fn visit_mod(&mut self, _: &hir::Mod<'tcx>, _: Span, _: hir::HirId) {

tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs

@@ -1,6 +1,9 @@
+// check-pass
+
 fn f() -> impl Sized {
-    enum E { //~ ERROR
+    enum E {
         V(E),
     }
+
     unimplemented!()
 }

tests/rustdoc-ui/infinite-recursive-type-impl-trait.stderr

@@ -0,0 +1,64 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/110422>.
+// This test ensures that inner items (except for implementations and macros)
+// don't appear in documentation.
+
+// compile-flags: --document-private-items
+
+#![crate_name = "foo"]
+
+// @has 'foo/index.html'
+// Checking there is no "trait" entry.
+// @count - '//*[@id="main-content"]/*[@class="small-section-header"]' 4
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Structs'
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Constants'
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Functions'
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Macros'
+
+// @has - '//a[@href="fn.foo.html"]' 'foo'
+fn foo() {
+    fn bar() {}
+
+    // @has - '//a[@class="macro"]' 'visible_macro'
+    // @!has - '//a[@class="macro"]' 'non_visible_macro'
+    // @has 'foo/macro.visible_macro.html'
+    // @!has 'foo/macro.non_visible_macro.html'
+    #[macro_export]
+    macro_rules! visible_macro {
+        () => {}
+    }
+
+    macro_rules! non_visible_macro {
+        () => {}
+    }
+}
+
+// @has 'foo/index.html'
+// @has - '//a[@href="struct.Bar.html"]' 'Bar'
+struct Bar;
+
+const BAR: i32 = {
+    // @!has - '//a[@href="fn.yo.html"]' 'yo'
+    // @!has 'foo/fn.yo.html'
+    fn yo() {}
+
+    // @!has 'foo/index.html' '//a[@href="trait.Foo.html"]' 'Foo'
+    // @!has 'foo/trait.Foo.html'
+    trait Foo {
+        fn babar() {}
+    }
+    impl Foo for Bar {}
+
+    // @has 'foo/struct.Bar.html'
+    // @has - '//*[@id="method.foo"]/*[@class="code-header"]' 'pub(crate) fn foo()'
+    // @count - '//*[@id="main-content"]/*[@class="small-section-header"]' 3
+    // We now check that the `Foo` trait is not documented nor visible on `Bar` page.
+    // @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Implementations'
+    // @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Auto Trait Implementations'
+    // @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Blanket Implementations'
+    // @!has - '//*[@href="trait.Foo.html#method.babar"]/*[@class="code-header"]' 'fn babar()'
+    impl Bar {
+        fn foo() {}
+    }
+
+    1
+};