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fix: make `expand_macro` multi-token mapping aware
| -rw-r--r-- | crates/ide/src/expand_macro.rs | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/crates/ide/src/expand_macro.rs b/crates/ide/src/expand_macro.rs index 5f34ba8391..fd9d1ff456 100644 --- a/crates/ide/src/expand_macro.rs +++ b/crates/ide/src/expand_macro.rs @@ -32,19 +32,32 @@ 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() { - if path == "derive" { - let mut tt = tt.syntax().children_with_tokens().skip(1).join(""); - tt.pop(); - let expansions = sema.expand_derive_macro(&attr)?; - return Some(ExpandedMacro { - name: tt, - expansion: expansions.into_iter().map(insert_whitespaces).join(""), - }); - } + // 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(); + let expansions = sema.expand_derive_macro(&attr)?; + return Some(ExpandedMacro { + 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 {} "#, |