Rollup merge of rust-lang#65857 - kinnison:kinnison/issue-55364, r=Manisheart,GuillaumeGomez

rustdoc: Resolve module-level doc references more locally

Module level docs should resolve intra-doc links as locally as
possible.  As such, this commit alters the heuristic for finding
intra-doc links such that we attempt to resolve names mentioned
in *inner* documentation comments within the (sub-)module rather
that from the context of its parent.

I'm hoping that this fixes rust-lang#55364 though right now I'm not sure it's the right fix.

r? @GuillaumeGomez

Author: tmandry

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -322,9 +322,26 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                     continue;
                 }
 
+                // In order to correctly resolve intra-doc-links we need to
+                // pick a base AST node to work from.  If the documentation for
+                // this module came from an inner comment (//!) then we anchor
+                // our name resolution *inside* the module.  If, on the other
+                // hand it was an outer comment (///) then we anchor the name
+                // resolution in the parent module on the basis that the names
+                // used are more likely to be intended to be parent names.  For
+                // this, we set base_node to None for inner comments since
+                // we've already pushed this node onto the resolution stack but
+                // for outer comments we explicitly try and resolve against the
+                // parent_node first.
+                let base_node = if item.is_mod() && item.attrs.inner_docs {
+                    None
+                } else {
+                    parent_node
+                };
+
                 match kind {
                     Some(ns @ ValueNS) => {
-                        if let Ok(res) = self.resolve(path_str, ns, &current_item, parent_node) {
+                        if let Ok(res) = self.resolve(path_str, ns, &current_item, base_node) {
                             res
                         } else {
                             resolution_failure(cx, &item, path_str, &dox, link_range);
@@ -335,7 +352,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                         }
                     }
                     Some(ns @ TypeNS) => {
-                        if let Ok(res) = self.resolve(path_str, ns, &current_item, parent_node) {
+                        if let Ok(res) = self.resolve(path_str, ns, &current_item, base_node) {
                             res
                         } else {
                             resolution_failure(cx, &item, path_str, &dox, link_range);
@@ -348,10 +365,10 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                         let candidates = PerNS {
                             macro_ns: macro_resolve(cx, path_str).map(|res| (res, None)),
                             type_ns: self
-                                .resolve(path_str, TypeNS, &current_item, parent_node)
+                                .resolve(path_str, TypeNS, &current_item, base_node)
                                 .ok(),
                             value_ns: self
-                                .resolve(path_str, ValueNS, &current_item, parent_node)
+                                .resolve(path_str, ValueNS, &current_item, base_node)
                                 .ok()
                                 .and_then(|(res, fragment)| {
                                     // Constructors are picked up in the type namespace.

src/test/rustdoc/issue-55364.rs

@@ -0,0 +1,88 @@
+// ignore-tidy-linelength
+
+// First a module with inner documentation
+
+// @has issue_55364/subone/index.html
+// These foo/bar links in the module's documentation should refer inside `subone`
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subone/fn.foo.html"]' 'foo'
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subone/fn.bar.html"]' 'bar'
+pub mod subone {
+    //! See either [foo] or [bar].
+
+    // This should refer to subone's `bar`
+    // @has issue_55364/subone/fn.foo.html
+    // @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subone/fn.bar.html"]' 'bar'
+    /// See [bar]
+    pub fn foo() {}
+    // This should refer to subone's `foo`
+    // @has issue_55364/subone/fn.bar.html
+    // @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subone/fn.foo.html"]' 'foo'
+    /// See [foo]
+    pub fn bar() {}
+}
+
+// A module with outer documentation
+
+// @has issue_55364/subtwo/index.html
+// These foo/bar links in the module's documentation should not reference inside `subtwo`
+// @!has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subtwo/fn.foo.html"]' 'foo'
+// @!has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subtwo/fn.bar.html"]' 'bar'
+// Instead it should be referencing the top level functions
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/fn.foo.html"]' 'foo'
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/fn.bar.html"]' 'bar'
+// Though there should be such links later
+// @has - '//section[@id="main"]/table//tr[@class="module-item"]/td/a[@class="fn"][@href="fn.foo.html"]' 'foo'
+// @has - '//section[@id="main"]/table//tr[@class="module-item"]/td/a[@class="fn"][@href="fn.bar.html"]' 'bar'
+/// See either [foo] or [bar].
+pub mod subtwo {
+
+    // Despite the module's docs referring to the top level foo/bar,
+    // this should refer to subtwo's `bar`
+    // @has issue_55364/subtwo/fn.foo.html
+    // @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subtwo/fn.bar.html"]' 'bar'
+    /// See [bar]
+    pub fn foo() {}
+    // Despite the module's docs referring to the top level foo/bar,
+    // this should refer to subtwo's `foo`
+    // @has issue_55364/subtwo/fn.bar.html
+    // @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/subtwo/fn.foo.html"]' 'foo'
+    /// See [foo]
+    pub fn bar() {}
+}
+
+// These are the function referred to by the module above with outer docs
+
+/// See [bar]
+pub fn foo() {}
+/// See [foo]
+pub fn bar() {}
+
+// This module refers to the outer foo/bar by means of `super::`
+
+// @has issue_55364/subthree/index.html
+// This module should also refer to the top level foo/bar
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/fn.foo.html"]' 'foo'
+// @has - '//section[@id="main"]/div[@class="docblock"]//a[@href="../../issue_55364/fn.bar.html"]' 'bar'
+pub mod subthree {
+    //! See either [foo][super::foo] or [bar][super::bar]
+}
+
+// Next we go *deeper* - In order to ensure it's not just "this or parent"
+// we test `crate::` and a `super::super::...` chain
+// @has issue_55364/subfour/subfive/subsix/subseven/subeight/index.html
+// @has - '//section[@id="main"]/table//tr[@class="module-item"]/td[@class="docblock-short"]//a[@href="../../../../../../issue_55364/subone/fn.foo.html"]' 'other foo'
+// @has - '//section[@id="main"]/table//tr[@class="module-item"]/td[@class="docblock-short"]//a[@href="../../../../../../issue_55364/subtwo/fn.bar.html"]' 'other bar'
+pub mod subfour {
+    pub mod subfive {
+        pub mod subsix {
+            pub mod subseven {
+                pub mod subeight {
+                    /// See [other foo][crate::subone::foo]
+                    pub fn foo() {}
+                    /// See [other bar][super::super::super::super::super::subtwo::bar]
+                    pub fn bar() {}
+                }
+            }
+        }
+    }
+}