Rollup merge of rust-lang#144970 - lolbinarycat:rustdoc-macro-wrong-link-144965, r=GuillaumeGomez

rustdoc: fix caching of intra-doc links on reexports

previously two reexports of the same item would share a set of intra-doc links, which would cause problems if they had two different links with the same text.  this was fixed by using the reexport defid as the key, if it is available.

fixes rust-lang#144965

Author: GuillaumeGomez

src/librustdoc/clean/types.rs

@@ -480,10 +480,28 @@ impl Item {
         }
     }
 
+    /// If the item has doc comments from a reexport, returns the item id of that reexport,
+    /// otherwise returns returns the item id.
+    ///
+    /// This is used as a key for caching intra-doc link resolution,
+    /// to prevent two reexports of the same item from using the same cache.
+    pub(crate) fn item_or_reexport_id(&self) -> ItemId {
+        // added documentation on a reexport is always prepended.
+        self.attrs
+            .doc_strings
+            .first()
+            .map(|x| x.item_id)
+            .flatten()
+            .map(ItemId::from)
+            .unwrap_or(self.item_id)
+    }
+
     pub(crate) fn links(&self, cx: &Context<'_>) -> Vec<RenderedLink> {
         use crate::html::format::{href, link_tooltip};
 
-        let Some(links) = cx.cache().intra_doc_links.get(&self.item_id) else { return vec![] };
+        let Some(links) = cx.cache().intra_doc_links.get(&self.item_or_reexport_id()) else {
+            return vec![];
+        };
         links
             .iter()
             .filter_map(|ItemLink { link: s, link_text, page_id: id, fragment }| {

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -1082,7 +1082,12 @@ impl LinkCollector<'_, '_> {
             for md_link in preprocessed_markdown_links(&doc) {
                 let link = self.resolve_link(&doc, item, item_id, module_id, &md_link);
                 if let Some(link) = link {
-                    self.cx.cache.intra_doc_links.entry(item.item_id).or_default().insert(link);
+                    self.cx
+                        .cache
+                        .intra_doc_links
+                        .entry(item.item_or_reexport_id())
+                        .or_default()
+                        .insert(link);
                 }
             }
         }

tests/rustdoc/intra-doc/macro-caching-144965.rs

@@ -0,0 +1,35 @@
+// regression test for https://github.com/rust-lang/rust/issues/144965
+
+#![crate_name = "foo"]
+#![no_std]
+
+#[doc(hidden)]
+pub struct MyStruct;
+
+macro_rules! my_macro {
+    () => {
+        pub fn my_function() {}
+
+        /// Incorrect: [`my_function()`].
+        #[doc(inline)]
+        pub use $crate::MyStruct;
+
+        /// Correct: [`my_function`].
+        pub struct AnotherStruct;
+    };
+}
+
+
+pub mod one {
+    //@ has 'foo/one/index.html'
+    //@ has - '//dl[@class="item-table"]/dd[1]/a[@href="fn.my_function.html"]/code' 'my_function'
+    //@ has - '//dl[@class="item-table"]/dd[2]/a[@href="fn.my_function.html"]/code' 'my_function()'
+    my_macro!();
+}
+
+pub mod two {
+    //@ has 'foo/two/index.html'
+    //@ has - '//dl[@class="item-table"]/dd[1]/a[@href="fn.my_function.html"]/code' 'my_function'
+    //@ has - '//dl[@class="item-table"]/dd[2]/a[@href="fn.my_function.html"]/code' 'my_function()'
+    my_macro!();
+}