Auto merge of #13481 - GuillaumeGomez:extern-map-fix, r=weihanglo

Add all unit's children recursively for `doc.extern-map` option

Fixes rust-lang/rust#120993.

It allows to fix link generation of reexport of foreign items when deps documentation is not generated. Sometimes, we need to have information about not only direct dependencies but also of dependencies of these direct dependencies and so on.

Author: bors

src/cargo/core/compiler/rustdoc.rs

@@ -102,6 +102,63 @@ impl hash::Hash for RustdocExternMap {
     }
 }
 
+/// Recursively generate html root url for all units and their children.
+///
+/// This is needed because in case there is a reexport of foreign reexport, you
+/// need to have information about grand-children deps level (deps of your deps).
+fn build_all_urls(
+    build_runner: &BuildRunner<'_, '_>,
+    rustdoc: &mut ProcessBuilder,
+    unit: &Unit,
+    name2url: &HashMap<&String, Url>,
+    map: &RustdocExternMap,
+    unstable_opts: &mut bool,
+) {
+    for dep in build_runner.unit_deps(unit) {
+        if !dep.unit.target.is_linkable() || dep.unit.mode.is_doc() {
+            continue;
+        }
+        for (registry, location) in &map.registries {
+            let sid = dep.unit.pkg.package_id().source_id();
+            let matches_registry = || -> bool {
+                if !sid.is_registry() {
+                    return false;
+                }
+                if sid.is_crates_io() {
+                    return registry == CRATES_IO_REGISTRY;
+                }
+                if let Some(index_url) = name2url.get(registry) {
+                    return index_url == sid.url();
+                }
+                false
+            };
+            if matches_registry() {
+                let mut url = location.clone();
+                if !url.contains("{pkg_name}") && !url.contains("{version}") {
+                    if !url.ends_with('/') {
+                        url.push('/');
+                    }
+                    url.push_str("{pkg_name}/{version}/");
+                }
+                let url = url
+                    .replace("{pkg_name}", &dep.unit.pkg.name())
+                    .replace("{version}", &dep.unit.pkg.version().to_string());
+                rustdoc.arg("--extern-html-root-url");
+                rustdoc.arg(format!("{}={}", dep.unit.target.crate_name(), url));
+                *unstable_opts = true;
+            }
+        }
+        build_all_urls(
+            build_runner,
+            rustdoc,
+            &dep.unit,
+            name2url,
+            map,
+            unstable_opts,
+        );
+    }
+}
+
 /// Adds unstable flag [`--extern-html-root-url`][1] to the given `rustdoc`
 /// invocation. This is for unstable feature [`-Zrustdoc-map`][2].
 ///
@@ -135,40 +192,14 @@ pub fn add_root_urls(
             }
         })
         .collect();
-    for dep in build_runner.unit_deps(unit) {
-        if dep.unit.target.is_linkable() && !dep.unit.mode.is_doc() {
-            for (registry, location) in &map.registries {
-                let sid = dep.unit.pkg.package_id().source_id();
-                let matches_registry = || -> bool {
-                    if !sid.is_registry() {
-                        return false;
-                    }
-                    if sid.is_crates_io() {
-                        return registry == CRATES_IO_REGISTRY;
-                    }
-                    if let Some(index_url) = name2url.get(registry) {
-                        return index_url == sid.url();
-                    }
-                    false
-                };
-                if matches_registry() {
-                    let mut url = location.clone();
-                    if !url.contains("{pkg_name}") && !url.contains("{version}") {
-                        if !url.ends_with('/') {
-                            url.push('/');
-                        }
-                        url.push_str("{pkg_name}/{version}/");
-                    }
-                    let url = url
-                        .replace("{pkg_name}", &dep.unit.pkg.name())
-                        .replace("{version}", &dep.unit.pkg.version().to_string());
-                    rustdoc.arg("--extern-html-root-url");
-                    rustdoc.arg(format!("{}={}", dep.unit.target.crate_name(), url));
-                    unstable_opts = true;
-                }
-            }
-        }
-    }
+    build_all_urls(
+        build_runner,
+        rustdoc,
+        unit,
+        &name2url,
+        map,
+        &mut unstable_opts,
+    );
     let std_url = match &map.std {
         None | Some(RustdocExternMode::Remote) => None,
         Some(RustdocExternMode::Local) => {

tests/testsuite/rustdoc_extern_html.rs

@@ -258,13 +258,9 @@ fn alt_registry() {
         .run();
     let queen = p.read_file("target/doc/foo/fn.queen.html");
     assert!(queen.contains(r#"href="https://example.com/bar/1.0.0/bar/struct.Queen.html""#));
-    // The king example fails to link. Rustdoc seems to want the origin crate
-    // name (baz) for re-exports. There are many issues in the issue tracker
-    // for rustdoc re-exports, so I'm not sure, but I think this is maybe a
-    // rustdoc issue. Alternatively, Cargo could provide mappings for all
-    // transitive dependencies to fix this.
+
     let king = p.read_file("target/doc/foo/fn.king.html");
-    assert!(king.contains(r#"-> King"#));
+    assert!(king.contains(r#"href="https://example.com/baz/1.0.0/baz/struct.King.html""#));
 
     let gold = p.read_file("target/doc/foo/fn.gold.html");
     assert!(gold.contains(r#"href="https://docs.rs/grimm/1.0.0/grimm/struct.Gold.html""#));
@@ -413,13 +409,9 @@ fn alt_sparse_registry() {
         .run();
     let queen = p.read_file("target/doc/foo/fn.queen.html");
     assert!(queen.contains(r#"href="https://example.com/bar/1.0.0/bar/struct.Queen.html""#));
-    // The king example fails to link. Rustdoc seems to want the origin crate
-    // name (baz) for re-exports. There are many issues in the issue tracker
-    // for rustdoc re-exports, so I'm not sure, but I think this is maybe a
-    // rustdoc issue. Alternatively, Cargo could provide mappings for all
-    // transitive dependencies to fix this.
+
     let king = p.read_file("target/doc/foo/fn.king.html");
-    assert!(king.contains(r#"-> King"#));
+    assert!(king.contains(r#"href="https://example.com/baz/1.0.0/baz/struct.King.html""#));
 
     let gold = p.read_file("target/doc/foo/fn.gold.html");
     assert!(gold.contains(r#"href="https://docs.rs/grimm/1.0.0/grimm/struct.Gold.html""#));