2 files changed, 63 insertions, 97 deletions

diff --git a/crates/ra_analysis/src/completion/mod.rs b/crates/ra_analysis/src/completion/mod.rs
index 2e082705e..e5ba92acd 100644
--- a/crates/ra_analysis/src/completion/mod.rs
+++ b/crates/ra_analysis/src/completion/mod.rs
@@ -2,18 +2,16 @@ mod reference_completion;
 
 use ra_editor::find_node_at_offset;
 use ra_syntax::{
-    algo::find_leaf_at_offset,
     algo::visit::{visitor_ctx, VisitorCtx},
     ast,
     AstNode, AtomEdit,
     SyntaxNodeRef,
 };
+use ra_db::SyntaxDatabase;
 use rustc_hash::{FxHashMap};
 
 use crate::{
-    db::{self, SyntaxDatabase},
-    descriptors::{DescriptorDatabase, module::ModuleSource},
-    input::{FilesDatabase},
+    db,
     Cancelable, FilePosition
 };
 
@@ -31,39 +29,21 @@ pub(crate) fn completions(
     db: &db::RootDatabase,
     position: FilePosition,
 ) -> Cancelable<Option<Vec<CompletionItem>>> {
-    let original_file = db.file_syntax(position.file_id);
+    let original_file = db.source_file(position.file_id);
     // Insert a fake ident to get a valid parse tree
     let file = {
         let edit = AtomEdit::insert(position.offset, "intellijRulezz".to_string());
         original_file.reparse(&edit)
     };
 
-    let leaf = match find_leaf_at_offset(original_file.syntax(), position.offset).left_biased() {
-        None => return Ok(None),
-        Some(it) => it,
-    };
-    let source_root_id = db.file_source_root(position.file_id);
-    let module_tree = db.module_tree(source_root_id)?;
-    let module_source = ModuleSource::for_node(position.file_id, leaf);
-    let module_id = match module_tree.any_module_for_source(module_source) {
-        None => return Ok(None),
-        Some(it) => it,
-    };
+    let module = ctry!(hir::Module::guess_from_position(db, position)?);
 
     let mut res = Vec::new();
     let mut has_completions = false;
     // First, let's try to complete a reference to some declaration.
     if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset) {
         has_completions = true;
-        reference_completion::completions(
-            &mut res,
-            db,
-            source_root_id,
-            &module_tree,
-            module_id,
-            &file,
-            name_ref,
-        )?;
+        reference_completion::completions(&mut res, db, &module, &file, name_ref)?;
         // special case, `trait T { fn foo(i_am_a_name_ref) {} }`
         if is_node::<ast::Param>(name_ref.syntax()) {
             param_completions(name_ref.syntax(), &mut res);
@@ -219,9 +199,9 @@ mod tests {
                 <|>
             }
             ",
-            r#"[CompletionItem { label: "Foo", lookup: None, snippet: None },
-                   CompletionItem { label: "Baz", lookup: None, snippet: None },
-                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#,
+            r#"[CompletionItem { label: "quux", lookup: None, snippet: None },
+                CompletionItem { label: "Foo", lookup: None, snippet: None },
+                CompletionItem { label: "Baz", lookup: None, snippet: None }]"#,
         );
     }
 
@@ -236,6 +216,20 @@ mod tests {
     }
 
     #[test]
+    fn test_completion_self_path() {
+        check_scope_completion(
+            r"
+            use self::m::<|>;
+
+            mod m {
+                struct Bar;
+            }
+            ",
+            r#"[CompletionItem { label: "Bar", lookup: None, snippet: None }]"#,
+        );
+    }
+
+    #[test]
     fn test_completion_mod_scope_nested() {
         check_scope_completion(
             r"
@@ -245,8 +239,8 @@ mod tests {
                 fn quux() { <|> }
             }
             ",
-            r#"[CompletionItem { label: "Bar", lookup: None, snippet: None },
-                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#,
+            r#"[CompletionItem { label: "quux", lookup: None, snippet: None },
+                CompletionItem { label: "Bar", lookup: None, snippet: None }]"#,
         );
     }
 
diff --git a/crates/ra_analysis/src/completion/reference_completion.rs b/crates/ra_analysis/src/completion/reference_completion.rs
index 6c5fd0be6..e1a2d5241 100644
--- a/crates/ra_analysis/src/completion/reference_completion.rs
+++ b/crates/ra_analysis/src/completion/reference_completion.rs
@@ -6,23 +6,23 @@ use ra_syntax::{
     ast::{self, LoopBodyOwner},
     SyntaxKind::*,
 };
+use     hir::{
+        self,
+        FnScopes,
+        Def,
+        Path,
+};
 
 use crate::{
     db::RootDatabase,
-    input::{SourceRootId},
     completion::CompletionItem,
-    descriptors::module::{ModuleId, ModuleTree},
-    descriptors::function::FnScopes,
-    descriptors::DescriptorDatabase,
     Cancelable
 };
 
 pub(super) fn completions(
     acc: &mut Vec<CompletionItem>,
     db: &RootDatabase,
-    source_root_id: SourceRootId,
-    module_tree: &ModuleTree,
-    module_id: ModuleId,
+    module: &hir::Module,
     file: &SourceFileNode,
     name_ref: ast::NameRef,
 ) -> Cancelable<()> {
@@ -40,25 +40,28 @@ pub(super) fn completions(
                 complete_expr_snippets(acc);
             }
 
-            let module_scope = db.module_scope(source_root_id, module_id)?;
+            let module_scope = module.scope(db)?;
             acc.extend(
                 module_scope
                     .entries()
-                    .iter()
-                    .filter(|entry| {
+                    .filter(|(_name, res)| {
                         // Don't expose this item
-                        !entry.ptr().range().is_subrange(&name_ref.syntax().range())
+                        match res.import {
+                            None => true,
+                            Some(import) => {
+                                let range = import.range(db, module.source().file_id());
+                                !range.is_subrange(&name_ref.syntax().range())
+                            }
+                        }
                     })
-                    .map(|entry| CompletionItem {
-                        label: entry.name().to_string(),
+                    .map(|(name, _res)| CompletionItem {
+                        label: name.to_string(),
                         lookup: None,
                         snippet: None,
                     }),
             );
         }
-        NameRefKind::CratePath(path) => {
-            complete_path(acc, db, source_root_id, module_tree, module_id, path)?
-        }
+        NameRefKind::Path(path) => complete_path(acc, db, module, path)?,
         NameRefKind::BareIdentInMod => {
             let name_range = name_ref.syntax().range();
             let top_node = name_ref
@@ -82,8 +85,8 @@ enum NameRefKind<'a> {
     LocalRef {
         enclosing_fn: Option<ast::FnDef<'a>>,
     },
-    /// NameRef is the last segment in crate:: path
-    CratePath(Vec<ast::NameRef<'a>>),
+    /// NameRef is the last segment in some path
+    Path(Path),
     /// NameRef is bare identifier at the module's root.
     /// Used for keyword completion
     BareIdentInMod,
@@ -105,8 +108,10 @@ fn classify_name_ref(name_ref: ast::NameRef) -> Option<NameRefKind> {
     let parent = name_ref.syntax().parent()?;
     if let Some(segment) = ast::PathSegment::cast(parent) {
         let path = segment.parent_path();
-        if let Some(crate_path) = crate_path(path) {
-            return Some(NameRefKind::CratePath(crate_path));
+        if let Some(path) = Path::from_ast(path) {
+            if !path.is_ident() {
+                return Some(NameRefKind::Path(path));
+            }
         }
         if path.qualifier().is_none() {
             let enclosing_fn = name_ref
@@ -120,32 +125,6 @@ fn classify_name_ref(name_ref: ast::NameRef) -> Option<NameRefKind> {
     None
 }
 
-fn crate_path(mut path: ast::Path) -> Option<Vec<ast::NameRef>> {
-    let mut res = Vec::new();
-    loop {
-        let segment = path.segment()?;
-        match segment.kind()? {
-            ast::PathSegmentKind::Name(name) => res.push(name),
-            ast::PathSegmentKind::CrateKw => break,
-            ast::PathSegmentKind::SelfKw | ast::PathSegmentKind::SuperKw => return None,
-        }
-        path = qualifier(path)?;
-    }
-    res.reverse();
-    return Some(res);
-
-    fn qualifier(path: ast::Path) -> Option<ast::Path> {
-        if let Some(q) = path.qualifier() {
-            return Some(q);
-        }
-        // TODO: this bottom up traversal is not too precise.
-        // Should we handle do a top-down analysiss, recording results?
-        let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
-        let use_tree = use_tree_list.parent_use_tree();
-        use_tree.path()
-    }
-}
-
 fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<CompletionItem>) {
     let mut shadowed = FxHashSet::default();
     acc.extend(
@@ -171,18 +150,24 @@ fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<Completi
 fn complete_path(
     acc: &mut Vec<CompletionItem>,
     db: &RootDatabase,
-    source_root_id: SourceRootId,
-    module_tree: &ModuleTree,
-    module_id: ModuleId,
-    crate_path: Vec<ast::NameRef>,
+    module: &hir::Module,
+    mut path: Path,
 ) -> Cancelable<()> {
-    let target_module_id = match find_target_module(module_tree, module_id, crate_path) {
+    if path.segments.is_empty() {
+        return Ok(());
+    }
+    path.segments.pop();
+    let def_id = match module.resolve_path(db, path)? {
         None => return Ok(()),
         Some(it) => it,
     };
-    let module_scope = db.module_scope(source_root_id, target_module_id)?;
-    let completions = module_scope.entries().iter().map(|entry| CompletionItem {
-        label: entry.name().to_string(),
+    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.entries().map(|(name, _res)| CompletionItem {
+        label: name.to_string(),
         lookup: None,
         snippet: None,
     });
@@ -190,19 +175,6 @@ fn complete_path(
     Ok(())
 }
 
-fn find_target_module(
-    module_tree: &ModuleTree,
-    module_id: ModuleId,
-    mut crate_path: Vec<ast::NameRef>,
-) -> Option<ModuleId> {
-    crate_path.pop();
-    let mut target_module = module_id.root(&module_tree);
-    for name in crate_path {
-        target_module = target_module.child(module_tree, name.text().as_str())?;
-    }
-    Some(target_module)
-}
-
 fn complete_mod_item_snippets(acc: &mut Vec<CompletionItem>) {
     acc.push(CompletionItem {
         label: "tfn".to_string(),