rustdoc::hidden_intra_doc_links now correctly handles indirect modules

lolbinarycat · lolbinarycat · commit 9be4ffa5dd67 · 2025-08-01T13:47:42.000-05:00
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
@@ -10,6 +10,7 @@
 use std::cmp::Ordering;
 use std::fmt::{self, Display, Write};
 use std::iter::{self, once};
+use std::ops::ControlFlow;
 use std::slice;
 
 use itertools::{Either, Itertools};
@@ -21,7 +22,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::{ConstStability, StabilityLevel, StableSince};
 use rustc_metadata::creader::{CStore, LoadedMacro};
-use rustc_middle::ty::{self, TyCtxt, TypingMode};
+use rustc_middle::ty::{self, ImplSubject, TyCtxt, TypingMode};
 use rustc_span::symbol::kw;
 use rustc_span::{Symbol, sym};
 use tracing::{debug, trace};
@@ -483,22 +484,80 @@ fn generate_item_def_id_path(
 
 /// Checks if the given defid refers to an item that is unnamable, such as one defined in a const block.
 fn is_unnamable(tcx: TyCtxt<'_>, did: DefId) -> bool {
+    traverse_parent(tcx, did, false, true, &|_| ControlFlow::Continue(()))
+}
+
+pub(crate) fn traverse_parent(
+    tcx: TyCtxt<'_>,
+    did: DefId,
+    if_noparent: bool,
+    if_unnamable: bool,
+    callback: &dyn Fn(DefId) -> ControlFlow<bool>,
+) -> bool {
     let mut cur_did = did;
     while let Some(parent) = tcx.opt_parent(cur_did) {
+        if let ControlFlow::Break(x) = callback(cur_did) {
+            return x;
+        }
         match tcx.def_kind(parent) {
             // items defined in these can be linked to, as long as they are visible
-            DefKind::Mod | DefKind::ForeignMod => cur_did = parent,
-            // items in impls can be linked to,
-            // as long as we can link to the item the impl is on.
-            // since associated traits are not a thing,
-            // it should not be possible to refer to an impl item if
-            // the base type is not namable.
-            DefKind::Impl { .. } => return false,
+            DefKind::Mod | DefKind::ForeignMod | DefKind::Trait => cur_did = parent,
+            // this serves both to future-proof is_unnamable for associated trait aliases,
+            // and traverses upwards to see if the trait or type is doc(hidden)
+            DefKind::Impl { .. } => {
+                match tcx.impl_subject(parent).as_ref().skip_binder() {
+                    ImplSubject::Trait(trait_ref) => {
+                        // first, check if the trait fufills the criteria
+                        if traverse_parent(
+                            tcx,
+                            trait_ref.def_id,
+                            if_noparent,
+                            if_unnamable,
+                            callback,
+                        ) {
+                            return true;
+                        }
+
+                        // for trait impls on local types, we also check if the type matches the criteria
+                        if let Some(hir::Node::Item(hir::Item {
+                            kind: hir::ItemKind::Impl(hir::Impl { self_ty, .. }),
+                            ..
+                        })) = tcx.hir_get_if_local(parent)
+                            && let hir::Ty {
+                                kind:
+                                    hir::TyKind::Path(hir::QPath::Resolved(
+                                        _,
+                                        hir::Path {
+                                            res: hir::def::Res::Def(_, self_ty_def_id),
+                                            ..
+                                        },
+                                    )),
+                                ..
+                            } = self_ty.peel_refs()
+                        /*&& let Some(local_def_id) = parent.as_local()
+                        && let Some(self_ty_def_id) = tcx.typeck(local_def_id).type_dependent_def_id(self_ty.hir_id)*/
+                        {
+                            cur_did = *self_ty_def_id;
+                            continue;
+                        }
+                        return if_noparent;
+                    }
+                    ImplSubject::Inherent(ty) => {
+                        if let Some(def_id) =
+                            rustc_middle::ty::print::characteristic_def_id_of_type(ty.peel_refs())
+                        {
+                            cur_did = def_id;
+                        } else {
+                            return if_noparent;
+                        }
+                    }
+                }
+            }
             // everything else does not have docs generated for it
-            _ => return true,
+            _ => return if_unnamable,
         }
     }
-    return false;
+    return if_noparent;
 }
 
 fn to_module_fqp(shortty: ItemType, fqp: &[Symbol]) -> &[Symbol] {
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -5,7 +5,7 @@
 use std::borrow::Cow;
 use std::fmt::Display;
 use std::mem;
-use std::ops::Range;
+use std::ops::{ControlFlow, Range};
 
 use pulldown_cmark::LinkType;
 use rustc_ast::util::comments::may_have_doc_links;
@@ -1351,7 +1351,8 @@ impl LinkCollector<'_, '_> {
             privacy_error(self.cx, diag_info, path_str, PrivacyErrorKind::Private);
         }
 
-        if self.cx.tcx.is_doc_hidden(id) && !self.cx.tcx.is_doc_hidden(src_def_id) {
+        if is_effectively_hidden(self.cx.tcx, id) && !is_effectively_hidden(self.cx.tcx, src_def_id)
+        {
             privacy_error(self.cx, diag_info, path_str, PrivacyErrorKind::Hidden);
         }
 
@@ -1596,6 +1597,13 @@ fn range_between_backticks(ori_link_range: &MarkdownLinkRange, dox: &str) -> Mar
     )
 }
 
+/// Is this item or any of its ancestors doc(hidden)?
+fn is_effectively_hidden(tcx: TyCtxt<'_>, id: DefId) -> bool {
+    crate::html::format::traverse_parent(tcx, id, false, false, &|id| {
+        if tcx.is_doc_hidden(id) { ControlFlow::Break(true) } else { ControlFlow::Continue(()) }
+    })
+}
+
 /// Returns true if we should ignore `link` due to it being unlikely
 /// that it is an intra-doc link. `link` should still have disambiguators
 /// if there were any.
diff --git a/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-both.stderr b/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-both.stderr
@@ -12,7 +12,7 @@ LL | #![deny(rustdoc::hidden_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
@@ -25,31 +25,31 @@ LL | #![deny(rustdoc::private_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link resolves only because you passed `--document-hidden-items`, but will break without
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:19:8
+  --> $DIR/link-to-hidden-144664.rs:22:8
    |
 LL | //! * [crate::local_private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
    |
    = note: this link resolves only because you passed `--document-private-items`, but will break without
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `nonlocal::public_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:21:8
+  --> $DIR/link-to-hidden-144664.rs:24:8
    |
 LL | //! * [nonlocal::public_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link resolves only because you passed `--document-hidden-items`, but will break without
 
 error: unresolved link to `nonlocal::private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:24:8
+  --> $DIR/link-to-hidden-144664.rs:28:8
    |
 LL | //! * [nonlocal::private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_hidden_fn` in module `hidden`
@@ -61,10 +61,32 @@ LL | #![deny(rustdoc::broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unresolved link to `nonlocal::private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:26:8
+  --> $DIR/link-to-hidden-144664.rs:30:8
    |
 LL | //! * [nonlocal::private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_non_hidden_fn` in module `hidden`
 
-error: aborting due to 7 previous errors
+error: unresolved link to `crate::hidden_mod::a`
+  --> $DIR/link-to-hidden-144664.rs:32:8
+   |
+LL | //! * [crate::hidden_mod::a]
+   |        ^^^^^^^^^^^^^^^^^^^^ no item named `a` in module `hidden_mod`
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::b`
+  --> $DIR/link-to-hidden-144664.rs:34:8
+   |
+LL | //! * [crate::hidden_mod::b]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link resolves only because you passed `--document-hidden-items`, but will break without
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::c`
+  --> $DIR/link-to-hidden-144664.rs:36:8
+   |
+LL | //! * [crate::hidden_mod::c]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link resolves only because you passed `--document-hidden-items`, but will break without
+
+error: aborting due to 10 previous errors
 
diff --git a/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-hidden.stderr b/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-hidden.stderr
@@ -12,7 +12,7 @@ LL | #![deny(rustdoc::hidden_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
@@ -25,31 +25,31 @@ LL | #![deny(rustdoc::private_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link will resolve properly if you pass `--document-hidden-items`
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:19:8
+  --> $DIR/link-to-hidden-144664.rs:22:8
    |
 LL | //! * [crate::local_private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
    |
    = note: this link will resolve properly if you pass `--document-private-items`
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `nonlocal::public_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:21:8
+  --> $DIR/link-to-hidden-144664.rs:24:8
    |
 LL | //! * [nonlocal::public_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link will resolve properly if you pass `--document-hidden-items`
 
 error: unresolved link to `nonlocal::private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:24:8
+  --> $DIR/link-to-hidden-144664.rs:28:8
    |
 LL | //! * [nonlocal::private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_hidden_fn` in module `hidden`
@@ -61,10 +61,32 @@ LL | #![deny(rustdoc::broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unresolved link to `nonlocal::private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:26:8
+  --> $DIR/link-to-hidden-144664.rs:30:8
    |
 LL | //! * [nonlocal::private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_non_hidden_fn` in module `hidden`
 
-error: aborting due to 7 previous errors
+error: unresolved link to `crate::hidden_mod::a`
+  --> $DIR/link-to-hidden-144664.rs:32:8
+   |
+LL | //! * [crate::hidden_mod::a]
+   |        ^^^^^^^^^^^^^^^^^^^^ no item named `a` in module `hidden_mod`
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::b`
+  --> $DIR/link-to-hidden-144664.rs:34:8
+   |
+LL | //! * [crate::hidden_mod::b]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link will resolve properly if you pass `--document-hidden-items`
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::c`
+  --> $DIR/link-to-hidden-144664.rs:36:8
+   |
+LL | //! * [crate::hidden_mod::c]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link will resolve properly if you pass `--document-hidden-items`
+
+error: aborting due to 10 previous errors
 
diff --git a/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-priv.stderr b/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.doc-priv.stderr
@@ -12,7 +12,7 @@ LL | #![deny(rustdoc::hidden_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
@@ -25,31 +25,31 @@ LL | #![deny(rustdoc::private_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::local_private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:16:8
+  --> $DIR/link-to-hidden-144664.rs:18:8
    |
 LL | //! * [crate::local_private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link resolves only because you passed `--document-hidden-items`, but will break without
 
 error: public documentation for `link_to_hidden_144664` links to private item `crate::local_private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:19:8
+  --> $DIR/link-to-hidden-144664.rs:22:8
    |
 LL | //! * [crate::local_private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
    |
    = note: this link resolves only because you passed `--document-private-items`, but will break without
 
 error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `nonlocal::public_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:21:8
+  --> $DIR/link-to-hidden-144664.rs:24:8
    |
 LL | //! * [nonlocal::public_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^ this item is hidden
    |
    = note: this link resolves only because you passed `--document-hidden-items`, but will break without
 
 error: unresolved link to `nonlocal::private_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:24:8
+  --> $DIR/link-to-hidden-144664.rs:28:8
    |
 LL | //! * [nonlocal::private_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_hidden_fn` in module `hidden`
@@ -61,10 +61,32 @@ LL | #![deny(rustdoc::broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unresolved link to `nonlocal::private_non_hidden_fn`
-  --> $DIR/link-to-hidden-144664.rs:26:8
+  --> $DIR/link-to-hidden-144664.rs:30:8
    |
 LL | //! * [nonlocal::private_non_hidden_fn]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `private_non_hidden_fn` in module `hidden`
 
-error: aborting due to 7 previous errors
+error: unresolved link to `crate::hidden_mod::a`
+  --> $DIR/link-to-hidden-144664.rs:32:8
+   |
+LL | //! * [crate::hidden_mod::a]
+   |        ^^^^^^^^^^^^^^^^^^^^ no item named `a` in module `hidden_mod`
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::b`
+  --> $DIR/link-to-hidden-144664.rs:34:8
+   |
+LL | //! * [crate::hidden_mod::b]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link resolves only because you passed `--document-hidden-items`, but will break without
+
+error: non-hidden documentation for `link_to_hidden_144664` links to hidden item `crate::hidden_mod::c`
+  --> $DIR/link-to-hidden-144664.rs:36:8
+   |
+LL | //! * [crate::hidden_mod::c]
+   |        ^^^^^^^^^^^^^^^^^^^^ this item is hidden
+   |
+   = note: this link resolves only because you passed `--document-hidden-items`, but will break without
+
+error: aborting due to 10 previous errors
 
diff --git a/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.noflags.stderr b/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.noflags.stderr
diff --git a/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.rs b/tests/rustdoc-ui/intra-doc/link-to-hidden-144664.rs
