Stop resolving doc links on `mod` items twice

compiler/rustc_resolve/src/late.rs

@@ -2199,7 +2199,11 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
     }
 
     fn resolve_item(&mut self, item: &'ast Item) {
-        self.resolve_doc_links(&item.attrs);
+        let mod_inner_docs =
+            matches!(item.kind, ItemKind::Mod(..)) && rustdoc::inner_docs(&item.attrs);
+        if !mod_inner_docs {
+            self.resolve_doc_links(&item.attrs);
+        }
 
         let name = item.ident.name;
         debug!("(resolving item) resolving {} ({:?})", name, item.kind);
@@ -2292,7 +2296,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
             ItemKind::Mod(..) => {
                 self.with_scope(item.id, |this| {
-                    this.resolve_doc_links(&item.attrs);
+                    if mod_inner_docs {
+                        this.resolve_doc_links(&item.attrs);
+                    }
                     let old_macro_rules = this.parent_scope.macro_rules;
                     visit::walk_item(this, item);
                     // Maintain macro_rules scopes in the same way as during early resolution

compiler/rustc_resolve/src/rustdoc.rs

@@ -326,6 +326,14 @@ pub fn strip_generics_from_path(path_str: &str) -> Result<String, MalformedGener
     if !stripped_path.is_empty() { Ok(stripped_path) } else { Err(MalformedGenerics::MissingType) }
 }
 
+/// Returns whether the first doc-comment is an inner attribute.
+///
+//// If there are no doc-comments, return true.
+/// FIXME(#78591): Support both inner and outer attributes on the same item.
+pub fn inner_docs(attrs: &[ast::Attribute]) -> bool {
+    attrs.iter().find(|a| a.doc_str().is_some()).map_or(true, |a| a.style == ast::AttrStyle::Inner)
+}
+
 /// Simplified version of the corresponding function in rustdoc.
 /// If the rustdoc version returns a successful result, this function must return the same result.
 /// Otherwise this function may return anything.

src/librustdoc/clean/types.rs

@@ -10,7 +10,7 @@ use std::{fmt, iter};
 use arrayvec::ArrayVec;
 use thin_vec::ThinVec;
 
-use rustc_ast::{self as ast, AttrStyle};
+use rustc_ast as ast;
 use rustc_attr::{ConstStability, Deprecation, Stability, StabilityLevel};
 use rustc_const_eval::const_eval::is_unstable_const_fn;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -23,7 +23,7 @@ use rustc_hir_analysis::check::intrinsic::intrinsic_operation_unsafety;
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::{self, DefIdTree, TyCtxt, Visibility};
-use rustc_resolve::rustdoc::{add_doc_fragment, attrs_to_doc_fragments, DocFragment};
+use rustc_resolve::rustdoc::{add_doc_fragment, attrs_to_doc_fragments, inner_docs, DocFragment};
 use rustc_session::Session;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
@@ -405,7 +405,7 @@ impl Item {
     pub(crate) fn inner_docs(&self, tcx: TyCtxt<'_>) -> bool {
         self.item_id
             .as_def_id()
-            .map(|did| tcx.get_attrs_unchecked(did).inner_docs())
+            .map(|did| inner_docs(tcx.get_attrs_unchecked(did)))
             .unwrap_or(false)
     }
 
@@ -874,8 +874,6 @@ pub(crate) trait AttributesExt {
 
     fn span(&self) -> Option<rustc_span::Span>;
 
-    fn inner_docs(&self) -> bool;
-
     fn cfg(&self, tcx: TyCtxt<'_>, hidden_cfg: &FxHashSet<Cfg>) -> Option<Arc<Cfg>>;
 }
 
@@ -894,14 +892,6 @@ impl AttributesExt for [ast::Attribute] {
         self.iter().find(|attr| attr.doc_str().is_some()).map(|attr| attr.span)
     }
 
-    /// Returns whether the first doc-comment is an inner attribute.
-    ///
-    //// If there are no doc-comments, return true.
-    /// FIXME(#78591): Support both inner and outer attributes on the same item.
-    fn inner_docs(&self) -> bool {
-        self.iter().find(|a| a.doc_str().is_some()).map_or(true, |a| a.style == AttrStyle::Inner)
-    }
-
     fn cfg(&self, tcx: TyCtxt<'_>, hidden_cfg: &FxHashSet<Cfg>) -> Option<Arc<Cfg>> {
         let sess = tcx.sess;
         let doc_cfg_active = tcx.features().doc_cfg;