7 files changed, 98 insertions, 32 deletions

diff --git a/crates/ra_analysis/src/completion/mod.rs b/crates/ra_analysis/src/completion/mod.rs
index c7717ab61..5ef278127 100644
--- a/crates/ra_analysis/src/completion/mod.rs
+++ b/crates/ra_analysis/src/completion/mod.rs
@@ -38,10 +38,7 @@ pub(crate) fn completions(
         original_file.reparse(&edit)
     };
 
-    let module = match ModuleDescriptor::guess_from_position(db, position)? {
-        None => return Ok(None),
-        Some(it) => it,
-    };
+    let module = ctry!(ModuleDescriptor::guess_from_position(db, position)?);
 
     let mut res = Vec::new();
     let mut has_completions = false;
diff --git a/crates/ra_analysis/src/completion/reference_completion.rs b/crates/ra_analysis/src/completion/reference_completion.rs
index 1faa70a18..858b52e76 100644
--- a/crates/ra_analysis/src/completion/reference_completion.rs
+++ b/crates/ra_analysis/src/completion/reference_completion.rs
@@ -13,6 +13,7 @@ use crate::{
     descriptors::{
         module::{ModuleDescriptor},
         function::FnScopes,
+        Def,
         Path,
     },
     Cancelable
@@ -42,8 +43,7 @@ pub(super) fn completions(
             let module_scope = module.scope(db)?;
             acc.extend(
                 module_scope
-                    .items
-                    .iter()
+                    .entries()
                     .filter(|(_name, res)| {
                         // Don't expose this item
                         match res.import {
@@ -157,19 +157,20 @@ fn complete_path(
         return Ok(());
     }
     path.segments.pop();
-    let target_module = match module.resolve_path(path) {
+    let def_id = match module.resolve_path(db, path)? {
         None => return Ok(()),
         Some(it) => it,
     };
+    let target_module = match def_id.resolve(db)? {
+        Def::Module(it) => it,
+        Def::Item => return Ok(()),
+    };
     let module_scope = target_module.scope(db)?;
-    let completions = module_scope
-        .items
-        .iter()
-        .map(|(name, _res)| CompletionItem {
-            label: name.to_string(),
-            lookup: None,
-            snippet: None,
-        });
+    let completions = module_scope.entries().map(|(name, _res)| CompletionItem {
+        label: name.to_string(),
+        lookup: None,
+        snippet: None,
+    });
     acc.extend(completions);
     Ok(())
 }
diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/descriptors/mod.rs
index 98094d9ee..7a1bcf447 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/descriptors/mod.rs
@@ -13,9 +13,12 @@ use crate::{
     FileId,
     db::SyntaxDatabase,
     descriptors::function::{resolve_local_name, FnId, FnScopes},
-    descriptors::module::{ModuleId, ModuleTree, ModuleSource, nameres::{ItemMap, InputModuleItems, FileItems}},
+    descriptors::module::{
+        ModuleId, ModuleTree, ModuleSource, ModuleDescriptor,
+        nameres::{ItemMap, InputModuleItems, FileItems}
+    },
     input::SourceRootId,
-    loc2id::IdDatabase,
+    loc2id::{IdDatabase, DefId, DefLoc},
     syntax_ptr::LocalSyntaxPtr,
     Cancelable,
 };
@@ -67,6 +70,25 @@ salsa::query_group! {
     }
 }
 
+pub(crate) enum Def {
+    Module(ModuleDescriptor),
+    Item,
+}
+
+impl DefId {
+    pub(crate) fn resolve(self, db: &impl DescriptorDatabase) -> Cancelable<Def> {
+        let loc = db.id_maps().def_loc(self);
+        let res = match loc {
+            DefLoc::Module { id, source_root } => {
+                let descr = ModuleDescriptor::new(db, source_root, id)?;
+                Def::Module(descr)
+            }
+            DefLoc::Item { .. } => Def::Item,
+        };
+        Ok(res)
+    }
+}
+
 #[derive(Debug)]
 pub struct ReferenceDescriptor {
     pub range: TextRange,
diff --git a/crates/ra_analysis/src/descriptors/module/mod.rs b/crates/ra_analysis/src/descriptors/module/mod.rs
index a6eaec178..78911d5d9 100644
--- a/crates/ra_analysis/src/descriptors/module/mod.rs
+++ b/crates/ra_analysis/src/descriptors/module/mod.rs
@@ -17,6 +17,7 @@ use crate::{
     descriptors::{Path, PathKind, DescriptorDatabase},
     input::SourceRootId,
     arena::{Arena, Id},
+    loc2id::{DefLoc, DefId},
 };
 
 pub(crate) use self::nameres::ModuleScope;
@@ -76,6 +77,20 @@ impl ModuleDescriptor {
         Ok(res)
     }
 
+    pub(super) fn new(
+        db: &impl DescriptorDatabase,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> Cancelable<ModuleDescriptor> {
+        let module_tree = db._module_tree(source_root_id)?;
+        let res = ModuleDescriptor {
+            tree: module_tree,
+            source_root_id,
+            module_id,
+        };
+        Ok(res)
+    }
+
     /// Returns `mod foo;` or `mod foo {}` node whihc declared this module.
     /// Returns `None` for the root module
     pub fn parent_link_source(
@@ -117,6 +132,14 @@ impl ModuleDescriptor {
         Some(link.name(&self.tree))
     }
 
+    pub fn def_id(&self, db: &impl DescriptorDatabase) -> DefId {
+        let def_loc = DefLoc::Module {
+            id: self.module_id,
+            source_root: self.source_root_id,
+        };
+        db.id_maps().def_id(def_loc)
+    }
+
     /// Finds a child module with the specified name.
     pub fn child(&self, name: &str) -> Option<ModuleDescriptor> {
         let child_id = self.module_id.child(&self.tree, name)?;
@@ -133,17 +156,28 @@ impl ModuleDescriptor {
         Ok(res)
     }
 
-    pub(crate) fn resolve_path(&self, path: Path) -> Option<ModuleDescriptor> {
+    pub(crate) fn resolve_path(
+        &self,
+        db: &impl DescriptorDatabase,
+        path: Path,
+    ) -> Cancelable<Option<DefId>> {
         let mut curr = match path.kind {
             PathKind::Crate => self.crate_root(),
             PathKind::Self_ | PathKind::Plain => self.clone(),
-            PathKind::Super => self.parent()?,
-        };
+            PathKind::Super => ctry!(self.parent()),
+        }
+        .def_id(db);
+
         let segments = path.segments;
-        for name in segments {
-            curr = curr.child(&name)?;
+        for name in segments.iter() {
+            let module = match db.id_maps().def_loc(curr) {
+                DefLoc::Module { id, source_root } => ModuleDescriptor::new(db, source_root, id)?,
+                _ => return Ok(None),
+            };
+            let scope = module.scope(db)?;
+            curr = ctry!(ctry!(scope.get(&name)).def_id);
         }
-        Some(curr)
+        Ok(Some(curr))
     }
 
     pub fn problems(&self, db: &impl DescriptorDatabase) -> Vec<(SyntaxNode, Problem)> {
diff --git a/crates/ra_analysis/src/descriptors/module/nameres.rs b/crates/ra_analysis/src/descriptors/module/nameres.rs
index d347a69b0..d2964f67f 100644
--- a/crates/ra_analysis/src/descriptors/module/nameres.rs
+++ b/crates/ra_analysis/src/descriptors/module/nameres.rs
@@ -103,7 +103,16 @@ pub(crate) struct ItemMap {
 
 #[derive(Debug, Default, PartialEq, Eq, Clone)]
 pub(crate) struct ModuleScope {
-    pub(crate) items: FxHashMap<SmolStr, Resolution>,
+    items: FxHashMap<SmolStr, Resolution>,
+}
+
+impl ModuleScope {
+    pub(crate) fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a SmolStr, &Resolution)> + 'a {
+        self.items.iter()
+    }
+    pub(crate) fn get(&self, name: &SmolStr) -> Option<&Resolution> {
+        self.items.get(name)
+    }
 }
 
 /// A set of items and imports declared inside a module, without relation to
diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index ad6b52371..8a41b3152 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -450,14 +450,8 @@ impl AnalysisImpl {
         let syntax = file.syntax();
 
         // Find the calling expression and it's NameRef
-        let calling_node = match FnCallNode::with_node(syntax, position.offset) {
-            Some(node) => node,
-            None => return Ok(None),
-        };
-        let name_ref = match calling_node.name_ref() {
-            Some(name) => name,
-            None => return Ok(None),
-        };
+        let calling_node = ctry!(FnCallNode::with_node(syntax, position.offset));
+        let name_ref = ctry!(calling_node.name_ref());
 
         // Resolve the function's NameRef (NOTE: this isn't entirely accurate).
         let file_symbols = self.index_resolve(name_ref)?;
diff --git a/crates/ra_analysis/src/lib.rs b/crates/ra_analysis/src/lib.rs
index cedbd1fc8..0fbfd8a40 100644
--- a/crates/ra_analysis/src/lib.rs
+++ b/crates/ra_analysis/src/lib.rs
@@ -9,6 +9,15 @@ extern crate relative_path;
 extern crate rustc_hash;
 extern crate salsa;
 
+macro_rules! ctry {
+    ($expr:expr) => {
+        match $expr {
+            None => return Ok(None),
+            Some(it) => it,
+        }
+    };
+}
+
 mod arena;
 mod db;
 mod loc2id;