1 files changed, 67 insertions, 0 deletions

diff --git a/crates/ra_hir_def/src/traits.rs b/crates/ra_hir_def/src/traits.rs
new file mode 100644
index 000000000..a8ba31594
--- /dev/null
+++ b/crates/ra_hir_def/src/traits.rs
@@ -0,0 +1,67 @@
+//! HIR for trait definitions.
+
+use std::sync::Arc;
+
+use hir_expand::name::{AsName, Name};
+
+use ra_syntax::ast::{self, NameOwner};
+use rustc_hash::FxHashMap;
+
+use crate::{
+    db::DefDatabase2, AssocItemId, AstItemDef, ConstId, FunctionId, LocationCtx, ModuleDefId,
+    ModuleId, TraitId, TypeAliasId,
+};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TraitData {
+    pub name: Option<Name>,
+    pub items: Vec<AssocItemId>,
+    pub auto: bool,
+}
+
+impl TraitData {
+    pub(crate) fn trait_data_query(db: &impl DefDatabase2, tr: TraitId) -> Arc<TraitData> {
+        let src = tr.source(db);
+        let name = src.value.name().map(|n| n.as_name());
+        let module = tr.module(db);
+        let ctx = LocationCtx::new(db, module, src.file_id);
+        let auto = src.value.is_auto();
+        let items = if let Some(item_list) = src.value.item_list() {
+            item_list
+                .impl_items()
+                .map(|item_node| match item_node {
+                    ast::ImplItem::FnDef(it) => FunctionId::from_ast(ctx, &it).into(),
+                    ast::ImplItem::ConstDef(it) => ConstId::from_ast(ctx, &it).into(),
+                    ast::ImplItem::TypeAliasDef(it) => TypeAliasId::from_ast(ctx, &it).into(),
+                })
+                .collect()
+        } else {
+            Vec::new()
+        };
+        Arc::new(TraitData { name, items, auto })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TraitItemsIndex {
+    traits_by_def: FxHashMap<AssocItemId, TraitId>,
+}
+
+impl TraitItemsIndex {
+    pub fn trait_items_index(db: &impl DefDatabase2, module: ModuleId) -> TraitItemsIndex {
+        let mut index = TraitItemsIndex { traits_by_def: FxHashMap::default() };
+        let crate_def_map = db.crate_def_map(module.krate);
+        for decl in crate_def_map[module.module_id].scope.declarations() {
+            if let ModuleDefId::TraitId(tr) = decl {
+                for item in db.trait_data(tr).items.iter() {
+                    index.traits_by_def.insert(*item, tr);
+                }
+            }
+        }
+        index
+    }
+
+    pub fn get_parent_trait(&self, item: AssocItemId) -> Option<TraitId> {
+        self.traits_by_def.get(&item).cloned()
+    }
+}