Merge #4660

4660: Enable hover and autocomplete docs on macro generated items r=aloucks a=aloucks

Enable hover and autocomplete docs on macro generated items. This de-sugars doc comments into `doc` attributes in some cases, but not all. Comments and `doc` attributes are then merged together. 

This PR is essentially a partial implementation of what's being suggested #3182, but it's not all the way there yet. ~I still need to add unit tests~, but I wanted to first get feedback on whether or not this was an acceptable path forward.

Fixes #4564
Fixes #3984
Fixes #3180
Related #3182

![macro_item_docs](https://user-images.githubusercontent.com/221559/83336760-15012200-a284-11ea-8d0d-b6a615850044.gif)



Co-authored-by: Aaron Loucks <[email protected]>

1 files changed, 7 insertions, 1 deletions

diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 8b6c0bede..2eeba0572 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -87,12 +87,18 @@ impl Attrs {
     }
 
     pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
+        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).doc_comment_text().map(
+            |docs_text| Attr {
+                input: Some(AttrInput::Literal(SmolStr::new(docs_text))),
+                path: ModPath::from(hir_expand::name!(doc)),
+            },
+        );
         let mut attrs = owner.attrs().peekable();
         let entries = if attrs.peek().is_none() {
             // Avoid heap allocation
             None
         } else {
-            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).chain(docs).collect())
         };
         Attrs { entries }
     }