[rustdoc] Allow to link to current crate

compiler/rustc_resolve/src/late.rs

@@ -4951,10 +4951,26 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                     path = &path[..idx];
                     need_traits_in_scope = true;
                     for ns in [TypeNS, ValueNS, MacroNS] {
-                        self.resolve_and_cache_rustdoc_path(path, ns);
+                        if let Some(res) = self.resolve_and_cache_rustdoc_path(path, ns) {
+                            // Rustdoc ignores tool attribute resolutions and attempts
+                            // to resolve their prefixes for diagnostics.
+                            any_resolved |=
+                                !matches!(res, Res::NonMacroAttr(NonMacroAttrKind::Tool));
+                        }
                     }
                 }
             }
+            // Only link to current crate if nothing else matched.
+            if !any_resolved && &*path_str == self.r.tcx.crate_name(LOCAL_CRATE).as_str() {
+                self.r
+                    .doc_link_resolutions
+                    .entry(self.parent_scope.module.nearest_parent_mod().expect_local())
+                    .or_default()
+                    .insert(
+                        (Symbol::intern(&path_str), ValueNS),
+                        Some(Res::Def(DefKind::Mod, CRATE_DEF_ID.to_def_id())),
+                    );
+            }
         }
 
         if need_traits_in_scope {

tests/rustdoc/intra-doc/auxiliary/intra-link-current-crate.rs

@@ -0,0 +1,5 @@
+#![deny(rustdoc::broken_intra_doc_links)]
+#![crate_name = "tarte"]
+
+/// [tarte]
+pub struct Tarte;

tests/rustdoc/intra-doc/link-to-current-crate.rs

@@ -0,0 +1,24 @@
+// Test to ensure that we can link to the current crate by using its name.
+//@ aux-build:intra-link-current-crate.rs
+//@ build-aux-docs
+
+#![deny(rustdoc::broken_intra_doc_links)]
+#![crate_name = "bar"]
+
+//@ has 'bar/index.html'
+//@ has - '//*[@class="docblock"]//a[@href="index.html"]' 'bar'
+//! [`bar`]
+
+extern crate tarte;
+
+//@ has 'bar/struct.Tarte.html'
+//@ has - '//*[@class="docblock"]//a[@href="../tarte/index.html"]' 'tarte'
+#[doc(inline)]
+pub use tarte::Tarte;
+
+pub mod foo {
+    //@ has 'bar/foo/fn.tadam.html'
+    //@ has - '//*[@class="docblock"]//a[@href="../index.html"]' 'bar'
+    /// [`bar`]
+    pub fn tadam() {}
+}