4 files changed, 83 insertions, 7 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index e8b3a1fb6..63e2e34e8 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -1,6 +1,6 @@
 use ra_db::{CrateId, Cancelable};
 
-use crate::{Module, Name, db::HirDatabase};
+use crate::{Name, db::HirDatabase, DefId};
 
 /// hir::Crate describes a single crate. It's the main inteface with which
 /// crate's dependencies interact. Mostly, it should be just a proxy for the
@@ -24,3 +24,24 @@ impl Crate {
         self.root_module_impl(db)
     }
 }
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Module {
+    pub(crate) def_id: DefId,
+}
+
+impl Module {
+    /// Returns the crate this module is part of.
+    pub fn krate(&self, db: &impl HirDatabase) -> Cancelable<Option<Crate>> {
+        self.krate_impl(db)
+    }
+
+    pub fn crate_root(&self, db: &impl HirDatabase) -> Cancelable<Module> {
+        self.crate_root_impl(db)
+    }
+
+    /// Finds a child module with the specified name.
+    pub fn child(&self, db: &impl HirDatabase, name: &Name) -> Cancelable<Option<Module>> {
+        self.child_impl(db, name)
+    }
+}
diff --git a/crates/ra_hir/src/code_model_impl.rs b/crates/ra_hir/src/code_model_impl.rs
index 75d4e04c1..22079ba33 100644
--- a/crates/ra_hir/src/code_model_impl.rs
+++ b/crates/ra_hir/src/code_model_impl.rs
@@ -1,6 +1,9 @@
 use ra_db::{CrateId, Cancelable};
 
-use crate::{Module, HirFileId, db::HirDatabase, Crate, CrateDependency, AsName};
+use crate::{HirFileId, db::HirDatabase, Crate, CrateDependency, AsName, DefId, DefLoc, DefKind, Name};
+
+use crate::code_model_api::Module;
+
 
 impl Crate {
     pub(crate) fn new(crate_id: CrateId) -> Crate {
@@ -28,7 +31,59 @@ impl Crate {
             .modules_with_sources()
             .find(|(_, src)| src.file_id() == file_id));
 
-        let module = Module::new(db, source_root_id, module_id)?;
+        let def_loc = DefLoc {
+            kind: DefKind::Module,
+            source_root_id,
+            module_id,
+            source_item_id: module_id.source(&module_tree).0,
+        };
+        let def_id = def_loc.id(db);
+
+        let module = Module::new(def_id);
+        Ok(Some(module))
+    }
+}
+
+impl Module {
+    fn new(def_id: DefId) -> Self {
+        crate::code_model_api::Module { def_id }
+    }
+
+    pub(crate) fn krate_impl(&self, db: &impl HirDatabase) -> Cancelable<Option<Crate>> {
+        let root = self.crate_root(db)?;
+        let loc = root.def_id.loc(db);
+        let file_id = loc.source_item_id.file_id.as_original_file();
+
+        let crate_graph = db.crate_graph();
+        let crate_id = ctry!(crate_graph.crate_id_for_crate_root(file_id));
+        Ok(Some(Crate::new(crate_id)))
+    }
+
+    pub(crate) fn crate_root_impl(&self, db: &impl HirDatabase) -> Cancelable<Module> {
+        let loc = self.def_id.loc(db);
+        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_id = loc.module_id.crate_root(&module_tree);
+        let def_loc = DefLoc {
+            module_id,
+            source_item_id: module_id.source(&module_tree).0,
+            ..loc
+        };
+        let def_id = def_loc.id(db);
+        let module = Module::new(def_id);
+        Ok(module)
+    }
+    /// Finds a child module with the specified name.
+    pub fn child_impl(&self, db: &impl HirDatabase, name: &Name) -> Cancelable<Option<Module>> {
+        let loc = self.def_id.loc(db);
+        let module_tree = db.module_tree(loc.source_root_id)?;
+        let child_id = ctry!(loc.module_id.child(&module_tree, name));
+        let def_loc = DefLoc {
+            module_id: child_id,
+            source_item_id: child_id.source(&module_tree).0,
+            ..loc
+        };
+        let def_id = def_loc.id(db);
+        let module = Module::new(def_id);
         Ok(Some(module))
     }
 }
diff --git a/crates/ra_hir/src/module.rs b/crates/ra_hir/src/module.rs
index b9821115c..f0b673908 100644
--- a/crates/ra_hir/src/module.rs
+++ b/crates/ra_hir/src/module.rs
@@ -224,7 +224,7 @@ impl ModuleTree {
 /// `ModuleSource` is the syntax tree element that produced this module:
 /// either a file, or an inlinde module.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct ModuleSource(SourceItemId);
+pub struct ModuleSource(pub(crate) SourceItemId);
 
 /// An owned syntax node for a module. Unlike `ModuleSource`,
 /// this holds onto the AST for the whole file.
@@ -255,12 +255,12 @@ impl ModuleId {
         let link = self.parent_link(tree)?;
         Some(tree.links[link].owner)
     }
-    fn crate_root(self, tree: &ModuleTree) -> ModuleId {
+    pub(crate) fn crate_root(self, tree: &ModuleTree) -> ModuleId {
         generate(Some(self), move |it| it.parent(tree))
             .last()
             .unwrap()
     }
-    fn child(self, tree: &ModuleTree, name: &Name) -> Option<ModuleId> {
+    pub(crate) fn child(self, tree: &ModuleTree, name: &Name) -> Option<ModuleId> {
         let link = tree.mods[self]
             .children
             .iter()
diff --git a/crates/ra_hir/src/module/nameres.rs b/crates/ra_hir/src/module/nameres.rs
index 3c6851a0a..cd634e42f 100644
--- a/crates/ra_hir/src/module/nameres.rs
+++ b/crates/ra_hir/src/module/nameres.rs
@@ -346,7 +346,7 @@ where
                 let krate = Crate::new(crate_id);
                 for dep in krate.dependencies(self.db) {
                     if let Some(module) = dep.krate.root_module(self.db)? {
-                        let def_id = module.def_id(self.db);
+                        let def_id = module.def_id;
                         self.add_module_item(
                             &mut module_items,
                             dep.name.clone(),