don't cache parses twice

Before this commit, `Parse`s for original file ended up two times in
salsa's db: first, when we parse original file, and second, when we
parse macro or a file.

Given that parse trees are the worst ofenders in terms of memory, it
makes sense to make sure we store them only once.

1 files changed, 3 insertions, 0 deletions

diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 872103219..3afd0994c 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -33,8 +33,11 @@ pub trait AstDatabase: SourceDatabase {
     #[salsa::transparent]
     #[salsa::invoke(crate::source_id::AstIdMap::file_item_query)]
     fn ast_id_to_node(&self, file_id: HirFileId, ast_id: ErasedFileAstId) -> TreeArc<SyntaxNode>;
+    #[salsa::transparent]
     #[salsa::invoke(crate::ids::HirFileId::parse_or_expand_query)]
     fn parse_or_expand(&self, file_id: HirFileId) -> Option<TreeArc<SyntaxNode>>;
+    #[salsa::invoke(crate::ids::HirFileId::parse_macro_query)]
+    fn parse_macro(&self, macro_file: ids::MacroFile) -> Option<TreeArc<SyntaxNode>>;
 
     #[salsa::invoke(crate::ids::macro_def_query)]
     fn macro_def(&self, macro_id: MacroDefId) -> Option<Arc<mbe::MacroRules>>;