Don't zone-register async callbacks for every await call in the VM.

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 6724 matching lines @@
       Scanner::kNoSourcePos, Symbols::AwaitContextVar(), dynamic_type);
   current_block_->scope->AddVariable(await_ctx_var);
   current_block_->scope->CaptureVariable(Symbols::AwaitContextVar());
   await_ctx_var->set_is_captured();
 }
 
 
 void Parser::AddAsyncClosureVariables() {
   // Add to current block's scope:
   //   var :async_op;
+  //   var :async_then_callback;
+  //   var :async_catch_error_callback;
   //   var :async_completer;
   const Type& dynamic_type = Type::ZoneHandle(Z, Type::DynamicType());
   LocalVariable* async_op_var = new(Z) LocalVariable(
       Scanner::kNoSourcePos, Symbols::AsyncOperation(), dynamic_type);
   current_block_->scope->AddVariable(async_op_var);
-  current_block_->scope->CaptureVariable(Symbols::AsyncOperation());
-  async_op_var->set_is_captured();
+  LocalVariable* async_then_callback_var = new(Z) LocalVariable(
+      Scanner::kNoSourcePos, Symbols::AsyncThenCallback(), dynamic_type);
+  current_block_->scope->AddVariable(async_then_callback_var);
+  current_block_->scope->CaptureVariable(Symbols::AsyncThenCallback());
+  async_then_callback_var->set_is_captured();
+  LocalVariable* async_catch_error_callback_var = new(Z) LocalVariable(
+      Scanner::kNoSourcePos, Symbols::AsyncCatchErrorCallback(), dynamic_type);
+  current_block_->scope->AddVariable(async_catch_error_callback_var);
+  current_block_->scope->CaptureVariable(Symbols::AsyncCatchErrorCallback());
+  async_catch_error_callback_var->set_is_captured();
   LocalVariable* async_completer = new(Z) LocalVariable(
       Scanner::kNoSourcePos, Symbols::AsyncCompleter(), dynamic_type);
   current_block_->scope->AddVariable(async_completer);
   current_block_->scope->CaptureVariable(Symbols::AsyncCompleter());
   async_completer->set_is_captured();
 }
 
 
 void Parser::AddAsyncGeneratorVariables() {
   // Add to current block's scope:
   //   var :controller;
   // The :controller variable is used by the async generator closure to
   // store the StreamController object to which the yielded expressions
   // are added.
   //   var :async_op;
-  // This variable is used to store the async generator closure containing
-  // the body of the async* function. It is used by the await operator.
+  //   var :async_then_callback;
+  //   var :async_catch_error_callback;
+  // These variables are used to store the async generator closure containing
+  // the body of the async* function. They are used by the await operator.
   const Type& dynamic_type = Type::ZoneHandle(Z, Type::DynamicType());
   LocalVariable* controller_var = new(Z) LocalVariable(
       Scanner::kNoSourcePos, Symbols::Controller(), dynamic_type);
   current_block_->scope->AddVariable(controller_var);
   current_block_->scope->CaptureVariable(Symbols::Controller());
   controller_var->set_is_captured();
 
   LocalVariable* async_op_var = new(Z) LocalVariable(
       Scanner::kNoSourcePos, Symbols::AsyncOperation(), dynamic_type);
   current_block_->scope->AddVariable(async_op_var);
-  current_block_->scope->CaptureVariable(Symbols::AsyncOperation());
-  async_op_var->set_is_captured();
+  LocalVariable* async_then_callback_var = new(Z) LocalVariable(
+      Scanner::kNoSourcePos, Symbols::AsyncThenCallback(), dynamic_type);
+  current_block_->scope->AddVariable(async_then_callback_var);
+  current_block_->scope->CaptureVariable(Symbols::AsyncThenCallback());
+  async_then_callback_var->set_is_captured();
+  LocalVariable* async_catch_error_callback_var = new(Z) LocalVariable(
+      Scanner::kNoSourcePos, Symbols::AsyncCatchErrorCallback(), dynamic_type);
+  current_block_->scope->AddVariable(async_catch_error_callback_var);
+  current_block_->scope->CaptureVariable(Symbols::AsyncCatchErrorCallback());
+  async_catch_error_callback_var->set_is_captured();
 }
 
 
 RawFunction* Parser::OpenAsyncGeneratorFunction(intptr_t async_func_pos) {
   TRACE_PARSER("OpenAsyncGeneratorFunction");
   AddContinuationVariables();
   AddAsyncGeneratorVariables();
 
   Function& closure = Function::Handle(Z);
   bool is_new_closure = false;
@@ skipping 61 matching lines @@
 // Generate the Ast nodes for the implicit code of the async* function.
 //
 // f(...) async* {
 //   var :controller;
 //   var :await_jump_var = -1;
 //   var :await_context_var;
 //   f_async_body() {
 //     ... source code of f ...
 //   }
 //   var :async_op = f_async_body;
+//   var :async_then_callback = _asyncThenWrapperHelper(:async_op);
+//   var :async_catch_error_callback = _asyncCatchErrorWrapperHelper(:async_op);
 //   :controller = new _AsyncStarStreamController(:async_op);
 //   return :controller.stream;
 // }
 SequenceNode* Parser::CloseAsyncGeneratorFunction(const Function& closure_func,
                                                   SequenceNode* closure_body) {
   TRACE_PARSER("CloseAsyncGeneratorFunction");
   ASSERT(!closure_func.IsNull());
   ASSERT(closure_body != NULL);
 
   // The block for the async closure body has already been closed. Close the
   // corresponding function block.
   CloseBlock();
 
   // Make sure the implicit variables of the async generator function
   // are captured.
   closure_body->scope()->LookupVariable(Symbols::AwaitJumpVar(), false);
   closure_body->scope()->LookupVariable(Symbols::AwaitContextVar(), false);
   closure_body->scope()->LookupVariable(Symbols::Controller(), false);
   closure_body->scope()->LookupVariable(Symbols::AsyncOperation(), false);
+  closure_body->scope()->LookupVariable(Symbols::AsyncThenCallback(), false);
+  closure_body->scope()->LookupVariable(
+      Symbols::AsyncCatchErrorCallback(), false);
+
+  const Library& async_lib = Library::Handle(Library::AsyncLibrary());
 
   const Class& controller_class = Class::Handle(Z,
-      Library::LookupCoreClass(Symbols::_AsyncStarStreamController()));
+      async_lib.LookupClassAllowPrivate(
+          Symbols::_AsyncStarStreamController()));
   ASSERT(!controller_class.IsNull());
   const Function& controller_constructor = Function::ZoneHandle(Z,
       controller_class.LookupConstructorAllowPrivate(
           Symbols::_AsyncStarStreamControllerConstructor()));
 
   // :await_jump_var = -1;
   LocalVariable* jump_var =
       current_block_->scope->LookupVariable(Symbols::AwaitJumpVar(), false);
   LiteralNode* init_value =
       new(Z) LiteralNode(Scanner::kNoSourcePos, Smi::ZoneHandle(Smi::New(-1)));
   current_block_->statements->Add(
       new(Z) StoreLocalNode(Scanner::kNoSourcePos, jump_var, init_value));
 
   // Add to AST:
   //   :async_op = <closure>;  (containing the original body)
   LocalVariable* async_op_var =
       current_block_->scope->LookupVariable(Symbols::AsyncOperation(), false);
   ClosureNode* closure_obj = new(Z) ClosureNode(
       Scanner::kNoSourcePos, closure_func, NULL, closure_body->scope());
   StoreLocalNode* store_async_op = new (Z) StoreLocalNode(
       Scanner::kNoSourcePos,
       async_op_var,
       closure_obj);
+
   current_block_->statements->Add(store_async_op);
 
+  // :async_then_callback = _asyncThenWrapperHelper(:async_op)
+  const Function& async_then_wrapper_helper = Function::ZoneHandle(
+      Z, async_lib.LookupFunctionAllowPrivate(
+          Symbols::AsyncThenWrapperHelper()));
+  ASSERT(!async_then_wrapper_helper.IsNull());
+  ArgumentListNode* async_then_wrapper_helper_args = new (Z) ArgumentListNode(
+      Scanner::kNoSourcePos);
+  async_then_wrapper_helper_args->Add(
+      new (Z) LoadLocalNode(Scanner::kNoSourcePos, async_op_var));
+  StaticCallNode* then_wrapper_call = new (Z) StaticCallNode(
+      Scanner::kNoSourcePos,
+      async_then_wrapper_helper,
+      async_then_wrapper_helper_args);
+  LocalVariable* async_then_callback_var =
+      current_block_->scope->LookupVariable(
+          Symbols::AsyncThenCallback(), false);
+  StoreLocalNode* store_async_then_callback = new (Z) StoreLocalNode(
+      Scanner::kNoSourcePos,
+      async_then_callback_var,
+      then_wrapper_call);
+
+  current_block_->statements->Add(store_async_then_callback);
+
+  // :async_catch_error_callback = _asyncErrorWrapperHelper(:async_op)
+
+  const Function& async_error_wrapper_helper = Function::ZoneHandle(
+      Z, async_lib.LookupFunctionAllowPrivate(
+          Symbols::AsyncErrorWrapperHelper()));
+  ASSERT(!async_error_wrapper_helper.IsNull());
+  ArgumentListNode* async_error_wrapper_helper_args = new (Z) ArgumentListNode(
+      Scanner::kNoSourcePos);
+  async_error_wrapper_helper_args->Add(
+      new (Z) LoadLocalNode(Scanner::kNoSourcePos, async_op_var));
+  StaticCallNode* error_wrapper_call = new (Z) StaticCallNode(
+      Scanner::kNoSourcePos,
+      async_error_wrapper_helper,
+      async_error_wrapper_helper_args);
+  LocalVariable* async_catch_error_callback_var =
+      current_block_->scope->LookupVariable(
+          Symbols::AsyncCatchErrorCallback(), false);
+  StoreLocalNode* store_async_catch_error_callback = new (Z) StoreLocalNode(
+      Scanner::kNoSourcePos,
+      async_catch_error_callback_var,
+      error_wrapper_call);
+
+  current_block_->statements->Add(store_async_catch_error_callback);
+
   // :controller = new _AsyncStarStreamController(body_closure);
   ArgumentListNode* arguments = new(Z) ArgumentListNode(Scanner::kNoSourcePos);
   arguments->Add(new (Z) LoadLocalNode(Scanner::kNoSourcePos, async_op_var));
   ConstructorCallNode* controller_constructor_call =
       new(Z) ConstructorCallNode(Scanner::kNoSourcePos,
                                  TypeArguments::ZoneHandle(Z),
                                  controller_constructor,
                                  arguments);
   LocalVariable* controller_var =
      current_block_->scope->LookupVariable(Symbols::Controller(), false);
@@ skipping 136 matching lines @@
   LocalVariable* async_op_var = current_block_->scope->LookupVariable(
       Symbols::AsyncOperation(), false);
   ClosureNode* cn = new(Z) ClosureNode(
       Scanner::kNoSourcePos, closure, NULL, closure_body->scope());
   StoreLocalNode* store_async_op = new (Z) StoreLocalNode(
       Scanner::kNoSourcePos,
       async_op_var,
       cn);
   current_block_->statements->Add(store_async_op);
 
+  const Library& async_lib = Library::Handle(Library::AsyncLibrary());
+  // :async_then_callback = _asyncThenWrapperHelper(:async_op)
+  const Function& async_then_wrapper_helper = Function::ZoneHandle(
+      Z, async_lib.LookupFunctionAllowPrivate(
+          Symbols::AsyncThenWrapperHelper()));
+  ASSERT(!async_then_wrapper_helper.IsNull());
+  ArgumentListNode* async_then_wrapper_helper_args = new (Z) ArgumentListNode(
+      Scanner::kNoSourcePos);
+  async_then_wrapper_helper_args->Add(
+      new (Z) LoadLocalNode(Scanner::kNoSourcePos, async_op_var));
+  StaticCallNode* then_wrapper_call = new (Z) StaticCallNode(
+      Scanner::kNoSourcePos,
+      async_then_wrapper_helper,
+      async_then_wrapper_helper_args);
+  LocalVariable* async_then_callback_var =
+      current_block_->scope->LookupVariable(
+          Symbols::AsyncThenCallback(), false);
+  StoreLocalNode* store_async_then_callback = new (Z) StoreLocalNode(
+      Scanner::kNoSourcePos,
+      async_then_callback_var,
+      then_wrapper_call);
+
+  current_block_->statements->Add(store_async_then_callback);
+
+  // :async_catch_error_callback = _asyncErrorWrapperHelper(:async_op)
+
+  const Function& async_error_wrapper_helper = Function::ZoneHandle(
+      Z, async_lib.LookupFunctionAllowPrivate(
+          Symbols::AsyncErrorWrapperHelper()));
+  ASSERT(!async_error_wrapper_helper.IsNull());
+  ArgumentListNode* async_error_wrapper_helper_args = new (Z) ArgumentListNode(
+      Scanner::kNoSourcePos);
+  async_error_wrapper_helper_args->Add(
+      new (Z) LoadLocalNode(Scanner::kNoSourcePos, async_op_var));
+  StaticCallNode* error_wrapper_call = new (Z) StaticCallNode(
+      Scanner::kNoSourcePos,
+      async_error_wrapper_helper,
+      async_error_wrapper_helper_args);
+  LocalVariable* async_catch_error_callback_var =
+      current_block_->scope->LookupVariable(
+          Symbols::AsyncCatchErrorCallback(), false);
+  StoreLocalNode* store_async_catch_error_callback = new (Z) StoreLocalNode(
+      Scanner::kNoSourcePos,
+      async_catch_error_callback_var,
+      error_wrapper_call);
+
+  current_block_->statements->Add(store_async_catch_error_callback);
+
   // Add to AST:
   //   new Future.microtask(:async_op);
   ArgumentListNode* arguments = new (Z) ArgumentListNode(Scanner::kNoSourcePos);
   arguments->Add(new (Z) LoadLocalNode(
       Scanner::kNoSourcePos, async_op_var));
   ConstructorCallNode* future_node = new (Z) ConstructorCallNode(
       Scanner::kNoSourcePos, TypeArguments::ZoneHandle(Z), constructor,
       arguments);
   current_block_->statements->Add(future_node);
 
@@ skipping 6989 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart