Allow using Self:: in doc

Author: Tymoteusz Jankowski

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -431,6 +431,43 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
 
         look_for_tests(&cx, &dox, &item, true);
 
+        // find item's parent to resolve `Self` in item's docs below
+        let parent_name = self.cx.as_local_hir_id(item.def_id).and_then(|item_hir| {
+            let parent_hir = self.cx.tcx.hir().get_parent_item(item_hir);
+            let item_parent = self.cx.tcx.hir().find(parent_hir);
+            match item_parent {
+                Some(hir::Node::Item(hir::Item {
+                    kind:
+                        hir::ItemKind::Impl {
+                            self_ty:
+                                hir::Ty {
+                                    kind:
+                                        hir::TyKind::Path(hir::QPath::Resolved(
+                                            _,
+                                            hir::Path { segments, .. },
+                                        )),
+                                    ..
+                                },
+                            ..
+                        },
+                    ..
+                })) => segments.first().and_then(|seg| Some(seg.ident.to_string())),
+                Some(hir::Node::Item(hir::Item {
+                    ident, kind: hir::ItemKind::Enum(..), ..
+                }))
+                | Some(hir::Node::Item(hir::Item {
+                    ident, kind: hir::ItemKind::Struct(..), ..
+                }))
+                | Some(hir::Node::Item(hir::Item {
+                    ident, kind: hir::ItemKind::Union(..), ..
+                }))
+                | Some(hir::Node::Item(hir::Item {
+                    ident, kind: hir::ItemKind::Trait(..), ..
+                })) => Some(ident.to_string()),
+                _ => None,
+            }
+        });
+
         for (ori_link, link_range) in markdown_links(&dox) {
             // Bail early for real links.
             if ori_link.contains('/') {
@@ -467,7 +504,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
             };
             let (res, fragment) = {
                 let mut kind = None;
-                let path_str = if let Some(prefix) =
+                let mut path_str = if let Some(prefix) =
                     ["struct@", "enum@", "type@", "trait@", "union@"]
                         .iter()
                         .find(|p| link.starts_with(**p))
@@ -521,6 +558,15 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                 let base_node =
                     if item.is_mod() && item.attrs.inner_docs { None } else { parent_node };
 
+                let resolved_self;
+                // replace `Self` with suitable item's parent name
+                if path_str.starts_with("Self::") {
+                    if let Some(ref name) = parent_name {
+                        resolved_self = format!("{}::{}", name, &path_str[6..]);
+                        path_str = &resolved_self;
+                    }
+                }
+
                 match kind {
                     Some(ns @ ValueNS) => {
                         match self.resolve(
@@ -529,7 +575,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                             &current_item,
                             base_node,
                             &extra_fragment,
-                            None,
+                            Some(&item),
                         ) {
                             Ok(res) => res,
                             Err(ErrorKind::ResolutionFailure) => {
@@ -552,7 +598,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                             &current_item,
                             base_node,
                             &extra_fragment,
-                            None,
+                            Some(&item),
                         ) {
                             Ok(res) => res,
                             Err(ErrorKind::ResolutionFailure) => {
@@ -577,7 +623,7 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
                                 &current_item,
                                 base_node,
                                 &extra_fragment,
-                                None,
+                                Some(&item),
                             ) {
                                 Err(ErrorKind::AnchorFailure(msg)) => {
                                     anchor_failure(cx, &item, &ori_link, &dox, link_range, msg);

src/test/rustdoc/intra-link-self.rs

@@ -1,5 +1,7 @@
 #![crate_name = "foo"]
 
+// ignore-tidy-linelength
+
 // @has foo/index.html '//a/@href' '../foo/struct.Foo.html#method.new'
 // @has foo/struct.Foo.html '//a/@href' '../foo/struct.Foo.html#method.new'
 
@@ -27,3 +29,89 @@ impl Bar {
         unimplemented!()
     }
 }
+
+pub struct MyStruct {
+    // @has foo/struct.MyStruct.html '//a/@href' '../foo/struct.MyStruct.html#structfield.struct_field'
+
+    /// [`struct_field`]
+    ///
+    /// [`struct_field`]: Self::struct_field
+    pub struct_field: u8,
+}
+
+pub enum MyEnum {
+    // @has foo/enum.MyEnum.html '//a/@href' '../foo/enum.MyEnum.html#EnumVariant.v'
+
+    /// [`EnumVariant`]
+    ///
+    /// [`EnumVariant`]: Self::EnumVariant
+    EnumVariant,
+}
+
+pub union MyUnion {
+    // @has foo/union.MyUnion.html '//a/@href' '../foo/union.MyUnion.html#structfield.union_field'
+
+    /// [`union_field`]
+    ///
+    /// [`union_field`]: Self::union_field
+    pub union_field: f32,
+}
+
+pub trait MyTrait {
+    // @has foo/trait.MyTrait.html '//a/@href' '../foo/trait.MyTrait.html#associatedtype.AssoType'
+
+    /// [`AssoType`]
+    ///
+    /// [`AssoType`]: Self::AssoType
+    type AssoType;
+
+    // @has foo/trait.MyTrait.html '//a/@href' '../foo/trait.MyTrait.html#associatedconstant.ASSO_CONST'
+
+    /// [`ASSO_CONST`]
+    ///
+    /// [`ASSO_CONST`]: Self::ASSO_CONST
+    const ASSO_CONST: i32 = 1;
+
+    // @has foo/trait.MyTrait.html '//a/@href' '../foo/trait.MyTrait.html#method.asso_fn'
+
+    /// [`asso_fn`]
+    ///
+    /// [`asso_fn`]: Self::asso_fn
+    fn asso_fn() {}
+}
+
+impl MyStruct {
+    // @has foo/struct.MyStruct.html '//a/@href' '../foo/struct.MyStruct.html#method.for_impl'
+
+    /// [`for_impl`]
+    ///
+    /// [`for_impl`]: Self::for_impl
+    pub fn for_impl() {
+        unimplemented!()
+    }
+}
+
+impl MyTrait for MyStruct {
+    // @has foo/struct.MyStruct.html '//a/@href' '../foo/struct.MyStruct.html#associatedtype.AssoType'
+
+    /// [`AssoType`]
+    ///
+    /// [`AssoType`]: Self::AssoType
+    type AssoType = u32;
+
+    // @has foo/struct.MyStruct.html '//a/@href' '../foo/struct.MyStruct.html#associatedconstant.ASSO_CONST'
+
+    /// [`ASSO_CONST`]
+    ///
+    /// [`ASSO_CONST`]: Self::ASSO_CONST
+    const ASSO_CONST: i32 = 10;
+
+    // @has foo/struct.MyStruct.html '//a/@href' '../foo/struct.MyStruct.html#method.asso_fn'
+
+    /// [`asso_fn`]
+    ///
+    /// [`asso_fn`]: Self::asso_fn
+    fn asso_fn() {
+        unimplemented!()
+    }
+}