1 files changed, 46 insertions, 0 deletions

diff --git a/crates/ra_hir_expand/src/db.rs b/crates/ra_hir_expand/src/db.rs
new file mode 100644
index 000000000..7133b61db
--- /dev/null
+++ b/crates/ra_hir_expand/src/db.rs
@@ -0,0 +1,46 @@
+use std::sync::Arc;
+
+use ra_db::{salsa, SourceDatabase};
+use ra_syntax::{Parse, SyntaxNode};
+
+use crate::{
+    ast_id_map::{AstIdMap, ErasedFileAstId},
+    expand::{HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroFile},
+};
+
+#[salsa::query_group(AstDatabaseStorage)]
+pub trait AstDatabase: SourceDatabase {
+    fn ast_id_map(&self, file_id: HirFileId) -> Arc<AstIdMap>;
+    #[salsa::transparent]
+    fn ast_id_to_node(&self, file_id: HirFileId, ast_id: ErasedFileAstId) -> SyntaxNode;
+
+    #[salsa::transparent]
+    #[salsa::invoke(crate::expand::parse_or_expand_query)]
+    fn parse_or_expand(&self, file_id: HirFileId) -> Option<SyntaxNode>;
+
+    #[salsa::interned]
+    fn intern_macro(&self, macro_call: MacroCallLoc) -> MacroCallId;
+    #[salsa::invoke(crate::expand::macro_arg_query)]
+    fn macro_arg(&self, id: MacroCallId) -> Option<Arc<tt::Subtree>>;
+    #[salsa::invoke(crate::expand::macro_def_query)]
+    fn macro_def(&self, id: MacroDefId) -> Option<Arc<mbe::MacroRules>>;
+    #[salsa::invoke(crate::expand::parse_macro_query)]
+    fn parse_macro(&self, macro_file: MacroFile) -> Option<Parse<SyntaxNode>>;
+    #[salsa::invoke(crate::expand::macro_expand_query)]
+    fn macro_expand(&self, macro_call: MacroCallId) -> Result<Arc<tt::Subtree>, String>;
+}
+
+pub(crate) fn ast_id_map(db: &impl AstDatabase, file_id: HirFileId) -> Arc<AstIdMap> {
+    let map =
+        db.parse_or_expand(file_id).map_or_else(AstIdMap::default, |it| AstIdMap::from_source(&it));
+    Arc::new(map)
+}
+
+pub(crate) fn ast_id_to_node(
+    db: &impl AstDatabase,
+    file_id: HirFileId,
+    ast_id: ErasedFileAstId,
+) -> SyntaxNode {
+    let node = db.parse_or_expand(file_id).unwrap();
+    db.ast_id_map(file_id)[ast_id].to_node(&node)
+}