Speed up completion

crates/ra_hir/src/semantics.rs

@@ -568,6 +568,7 @@ fn find_root(node: &SyntaxNode) -> SyntaxNode {
     node.ancestors().last().unwrap()
 }
 
+#[derive(Debug)]
 pub struct SemanticsScope<'a> {
     pub db: &'a dyn HirDatabase,
     resolver: Resolver,

crates/ra_ide/src/completion/complete_attribute.rs

@@ -195,7 +195,7 @@ fn parse_derive_input(derive_input: ast::TokenTree) -> Result<FxHashSet<String>,
 
 fn get_derive_names_in_scope(ctx: &CompletionContext) -> FxHashSet<String> {
     let mut result = FxHashSet::default();
-    ctx.scope().process_all_names(&mut |name, scope_def| {
+    ctx.scope.process_all_names(&mut |name, scope_def| {
         if let hir::ScopeDef::MacroDef(mac) = scope_def {
             if mac.is_derive_macro() {
                 result.insert(name.to_string());

crates/ra_ide/src/completion/complete_dot.rs

@@ -29,7 +29,7 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
 fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     for receiver in receiver.autoderef(ctx.db) {
         for (field, ty) in receiver.fields(ctx.db) {
-            if ctx.scope().module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
+            if ctx.scope.module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
                 // Skip private field. FIXME: If the definition location of the
                 // field is editable, we should show the completion
                 continue;
@@ -46,10 +46,10 @@ fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Ty
 fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     if let Some(krate) = ctx.krate {
         let mut seen_methods = FxHashSet::default();
-        let traits_in_scope = ctx.scope().traits_in_scope();
+        let traits_in_scope = ctx.scope.traits_in_scope();
         receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
             if func.has_self_param(ctx.db)
-                && ctx.scope().module().map_or(true, |m| func.is_visible_from(ctx.db, m))
+                && ctx.scope.module().map_or(true, |m| func.is_visible_from(ctx.db, m))
                 && seen_methods.insert(func.name(ctx.db))
             {
                 acc.add_function(ctx, func, None);

crates/ra_ide/src/completion/complete_macro_in_item_position.rs

@@ -5,7 +5,7 @@ use crate::completion::{CompletionContext, Completions};
 pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &CompletionContext) {
     // Show only macros in top level.
     if ctx.is_new_item {
-        ctx.scope().process_all_names(&mut |name, res| {
+        ctx.scope.process_all_names(&mut |name, res| {
             if let hir::ScopeDef::MacroDef(mac) = res {
                 acc.add_macro(ctx, Some(name.to_string()), mac);
             }

crates/ra_ide/src/completion/complete_pattern.rs

@@ -13,7 +13,7 @@ pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
 
     // FIXME: ideally, we should look at the type we are matching against and
     // suggest variants + auto-imports
-    ctx.scope().process_all_names(&mut |name, res| {
+    ctx.scope.process_all_names(&mut |name, res| {
         match &res {
             hir::ScopeDef::ModuleDef(def) => match def {
                 hir::ModuleDef::Adt(hir::Adt::Enum(..))

crates/ra_ide/src/completion/complete_qualified_path.rs

@@ -17,21 +17,20 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
         return;
     }
 
-    let scope = ctx.scope();
+    let context_module = ctx.scope.module();
-    let context_module = scope.module();
 
-    let res = match scope.resolve_hir_path_qualifier(&path) {
+    let resolution = match ctx.scope.resolve_hir_path_qualifier(&path) {
         Some(res) => res,
         None => return,
     };
 
     // Add associated types on type parameters and `Self`.
-    res.assoc_type_shorthand_candidates(ctx.db, |alias| {
+    resolution.assoc_type_shorthand_candidates(ctx.db, |alias| {
         acc.add_type_alias(ctx, alias);
         None::<()>
     });
 
-    match res {
+    match resolution {
         PathResolution::Def(hir::ModuleDef::Module(module)) => {
             let module_scope = module.scope(ctx.db, context_module);
             for (name, def) in module_scope {
@@ -68,7 +67,7 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 
             let krate = ctx.krate;
             if let Some(krate) = krate {
-                let traits_in_scope = ctx.scope().traits_in_scope();
+                let traits_in_scope = ctx.scope.traits_in_scope();
                 ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
                         return None;
@@ -113,13 +112,13 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
         }
         PathResolution::TypeParam(_) | PathResolution::SelfType(_) => {
             if let Some(krate) = ctx.krate {
-                let ty = match res {
+                let ty = match resolution {
                     PathResolution::TypeParam(param) => param.ty(ctx.db),
                     PathResolution::SelfType(impl_def) => impl_def.target_ty(ctx.db),
                     _ => return,
                 };
 
-                let traits_in_scope = ctx.scope().traits_in_scope();
+                let traits_in_scope = ctx.scope.traits_in_scope();
                 let mut seen = FxHashSet::default();
                 ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {

crates/ra_ide/src/completion/complete_unqualified_path.rs

@@ -25,7 +25,7 @@ pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         return;
     }
 
-    ctx.scope().process_all_names(&mut |name, res| {
+    ctx.scope.process_all_names(&mut |name, res| {
         if ctx.use_item_syntax.is_some() {
             if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
                 if name_ref.syntax().text() == name.to_string().as_str() {
@@ -42,7 +42,7 @@ fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &T
     if let Some(Adt::Enum(enum_data)) = ty.as_adt() {
         let variants = enum_data.variants(ctx.db);
 
-        let module = if let Some(module) = ctx.scope().module() {
+        let module = if let Some(module) = ctx.scope.module() {
             // Compute path from the completion site if available.
             module
         } else {

crates/ra_ide/src/completion/completion_context.rs

@@ -24,6 +24,7 @@ use test_utils::mark;
 #[derive(Debug)]
 pub(crate) struct CompletionContext<'a> {
     pub(super) sema: Semantics<'a, RootDatabase>,
+    pub(super) scope: SemanticsScope<'a>,
     pub(super) db: &'a RootDatabase,
     pub(super) config: &'a CompletionConfig,
     pub(super) offset: TextSize,
@@ -106,8 +107,10 @@ impl<'a> CompletionContext<'a> {
         let original_token =
             original_file.syntax().token_at_offset(position.offset).left_biased()?;
         let token = sema.descend_into_macros(original_token.clone());
+        let scope = sema.scope_at_offset(&token.parent(), position.offset);
         let mut ctx = CompletionContext {
             sema,
+            scope,
             db,
             config,
             original_token,
@@ -207,10 +210,6 @@ impl<'a> CompletionContext<'a> {
         }
     }
 
-    pub(crate) fn scope(&self) -> SemanticsScope<'_> {
-        self.sema.scope_at_offset(&self.token.parent(), self.offset)
-    }
-
     fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) {
         let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap();
         let syntax_element = NodeOrToken::Token(fake_ident_token.clone());