rustdoc: Inherit inline attributes for declarative macros

src/librustdoc/clean/mod.rs

@@ -176,6 +176,35 @@ fn is_glob_import(tcx: TyCtxt<'_>, import_id: LocalDefId) -> bool {
     }
 }
 
+/// Returns true if `def_id` is a macro and should be inlined.
+pub(crate) fn macro_reexport_is_inline(
+    tcx: TyCtxt<'_>,
+    import_id: LocalDefId,
+    def_id: DefId,
+) -> bool {
+    if !matches!(tcx.def_kind(def_id), DefKind::Macro(MacroKinds::BANG)) {
+        return false;
+    }
+
+    for reexport_def_id in reexport_chain(tcx, import_id, def_id).iter().flat_map(|r| r.id()) {
+        let is_hidden = tcx.is_doc_hidden(reexport_def_id);
+        let is_inline = find_attr!(
+            inline::load_attrs(tcx, reexport_def_id),
+            Doc(d)
+            if d.inline.first().is_some_and(|(inline, _)| *inline == DocInline::Inline)
+        );
+
+        // hidden takes absolute priority over inline on the same node
+        if is_hidden {
+            return false;
+        }
+        if is_inline {
+            return true;
+        }
+    }
+    false
+}
+
 fn generate_item_with_correct_attrs(
     cx: &mut DocContext<'_>,
     kind: ItemKind,
@@ -201,7 +230,8 @@ fn generate_item_with_correct_attrs(
                 Doc(d)
                 if d.inline.first().is_some_and(|(inline, _)| *inline == DocInline::Inline)
             ) || (is_glob_import(tcx, import_id)
-                && (cx.document_hidden() || !tcx.is_doc_hidden(def_id)));
+                && (cx.document_hidden() || !tcx.is_doc_hidden(def_id)))
+                || macro_reexport_is_inline(tcx, import_id, def_id);
             attrs.extend(get_all_import_attributes(cx, import_id, def_id, is_inline));
             is_inline = is_inline || import_is_inline;
         }

src/librustdoc/visit_ast.rs

@@ -478,11 +478,21 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                     // If there was a private module in the current path then don't bother inlining
                     // anything as it will probably be stripped anyway.
                     if is_pub && self.inside_public_path {
-                        let please_inline = find_attr!(
-                            attrs,
-                            Doc(d)
-                            if d.inline.first().is_some_and(|(inline, _)| *inline == DocInline::Inline)
-                        );
+                        let please_inline = if let Some(res_did) = res.opt_def_id()
+                            && matches!(tcx.def_kind(res_did), DefKind::Macro(MacroKinds::BANG))
+                        {
+                            crate::clean::macro_reexport_is_inline(
+                                tcx,
+                                item.owner_id.def_id,
+                                res_did,
+                            )
+                        } else {
+                            find_attr!(
+                                attrs,
+                                Doc(d)
+                                if d.inline.first().is_some_and(|(inline, _)| *inline == DocInline::Inline)
+                            )
+                        };
                         let ident = match kind {
                             hir::UseKind::Single(ident) => Some(ident.name),
                             hir::UseKind::Glob => None,

tests/rustdoc-html/macro-reexport-inline.rs

@@ -0,0 +1,129 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/154694>.
+// The goal is to ensure that declarative macros re-exported by name
+// inherit the `#[doc(inline)]` attribute from intermediate re-exports,
+// matching the behavior of glob re-exports.
+
+#![crate_name = "foo"]
+
+#[macro_use]
+mod macros {
+    #[macro_export]
+    #[doc(hidden)]
+    macro_rules! explicit_macro {
+        () => {};
+    }
+
+    #[macro_export]
+    #[doc(hidden)]
+    macro_rules! wild_macro {
+        () => {};
+    }
+
+    #[macro_export]
+    #[doc(hidden)]
+    macro_rules! actually_hidden_macro {
+        () => {};
+    }
+
+    #[macro_export]
+    #[doc(hidden)]
+    macro_rules! actually_hidden_wild_macro {
+        () => {};
+    }
+
+    #[macro_export]
+    #[doc(hidden)]
+    macro_rules! actually_hidden_indirect_macro {
+        () => {};
+    }
+}
+
+// Standard items (like structs) are provided as control cases to ensure
+// macro inlining behavior maintains parity.
+#[doc(hidden)]
+pub struct HiddenStruct;
+
+#[doc(hidden)]
+pub struct IndirectlyHiddenStruct;
+
+pub mod bar {
+    mod hidden_explicit {
+        #[doc(inline)]
+        pub use crate::explicit_macro;
+    }
+
+    mod hidden_wild {
+        #[doc(inline)]
+        pub use crate::wild_macro;
+    }
+
+    mod actually_hidden {
+        // BUG: as demonstrated by the `actually_hidden_struct` module, when both
+        // `doc(hidden)` and `doc(inline)` are specified, `doc(hidden)`
+        // should take priority.
+        #[doc(hidden)]
+        #[doc(inline)]
+        pub use crate::actually_hidden_macro;
+    }
+
+    mod actually_hidden_indirect_inner {
+        #[doc(inline)]
+        pub use crate::actually_hidden_indirect_macro;
+    }
+
+    mod actually_hidden_indirect {
+        // BUG: when there is a chain of imports, we should stop looking as soon as soon as we hit
+        // something with `doc(hidden)`.
+        #[doc(hidden)]
+        pub use super::actually_hidden_indirect_inner::actually_hidden_indirect_macro;
+    }
+
+    mod actually_hidden_indirect_struct_inner {
+        #[doc(inline)]
+        pub use crate::IndirectlyHiddenStruct;
+    }
+
+    mod actually_hidden_indirect_struct {
+        #[doc(hidden)]
+        pub use super::actually_hidden_indirect_struct_inner::IndirectlyHiddenStruct;
+    }
+
+    mod actually_hidden_wild {
+        #[doc(hidden)]
+        #[doc(inline)]
+        pub use crate::actually_hidden_wild_macro;
+    }
+
+    mod actually_hidden_struct {
+        #[doc(inline)]
+        #[doc(hidden)]
+        pub use crate::HiddenStruct;
+    }
+
+    // First, we check that the explicitly named macro inherits the inline attribute
+    // from `hidden_explicit` and is successfully rendered.
+    //@ has 'foo/bar/macro.explicit_macro.html'
+    //@ has 'foo/bar/index.html' '//a[@href="macro.explicit_macro.html"]' 'explicit_macro'
+    pub use self::hidden_explicit::explicit_macro;
+
+    // Next, we ensure that the glob-imported macro continues to render correctly
+    // as a control case.
+    //@ has 'foo/bar/macro.wild_macro.html'
+    //@ has 'foo/bar/index.html' '//a[@href="macro.wild_macro.html"]' 'wild_macro'
+    pub use self::hidden_wild::*;
+
+    //@ !has 'foo/bar/macro.actually_hidden_macro.html'
+    pub use self::actually_hidden::actually_hidden_macro;
+
+    //@ !has 'foo/bar/macro.actually_hidden_wild_macro.html'
+    pub use self::actually_hidden_wild::*;
+
+    //@ !has 'foo/bar/struct.HiddenStruct.html'
+    pub use self::actually_hidden_struct::HiddenStruct;
+
+    //@ !has 'foo/bar/macro.actually_hidden_indirect_macro.html'
+    pub use self::actually_hidden_indirect::actually_hidden_indirect_macro;
+
+    //@ !has 'foo/bar/struct.IndirectlyHiddenStruct.html'
+    pub use self::actually_hidden_indirect_struct::IndirectlyHiddenStruct;
+}