fix: make `expand_macro` multi-token mapping aware
@@ -32,9 +32,17 @@ pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<
_ => 0,
})?;
- let descended = sema.descend_into_macros_single(tok.clone());
- if let Some(attr) = descended.ancestors().find_map(ast::Attr::cast) {
- if let Some((path, tt)) = attr.as_simple_call() {
+ // due to how Rust Analyzer works internally, we need to special case derive attributes,
+ // otherwise they might not get found, e.g. here only `#[attr]` would expand:
+ // ```
+ // #[attr]
+ // #[derive($0Foo)]
+ // struct Bar;
+ // ```
+
+ let derive = sema.descend_into_macros(tok.clone()).iter().find_map(|descended| {
+ let attr = descended.ancestors().find_map(ast::Attr::cast)?;
+ let (path, tt) = attr.as_simple_call()?;
if path == "derive" {
let mut tt = tt.syntax().children_with_tokens().skip(1).join("");
tt.pop();
@@ -43,8 +51,13 @@ pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<
name: tt,
expansion: expansions.into_iter().map(insert_whitespaces).join(""),
});
+ } else {
+ None
}
- }
+ });
+
+ if derive.is_some() {
+ return derive;
}
// FIXME: Intermix attribute and bang! expansions
@@ -356,6 +369,7 @@ fn main() {
#[rustc_builtin_macro]
pub macro Clone {}
+#[doc = ""]
#[derive(C$0lone)]
struct Foo {}
"#,
