Await it!

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 5408 matching lines @@
                                   current_block_->scope->function_level() + 1,
                                   0);
   }
   ChainNewBlock(outer_scope);
 }
 
 
 void Parser::OpenAsyncClosure() {
   TRACE_PARSER("OpenAsyncClosure");
   parsed_function()->set_await_temps_scope(current_block_->scope);
-  // TODO(mlippautz): Set up explicit jump table for await continuations.
 }
 
 
 RawFunction* Parser::OpenAsyncFunction(intptr_t formal_param_pos) {
   TRACE_PARSER("OpenAsyncFunction");
   // Create the closure containing the old body of this function.
   Class& sig_cls = Class::ZoneHandle(I);
   Type& sig_type = Type::ZoneHandle(I);
   Function& closure = Function::ZoneHandle(I);
   String& sig = String::ZoneHandle(I);
@@ skipping 76 matching lines @@
   const Class& completer = Class::ZoneHandle(I,
       GetClassForAsync(Symbols::Completer()));
   ASSERT(!completer.IsNull());
   const Function& completer_constructor = Function::ZoneHandle(I,
       completer.LookupFunction(Symbols::CompleterConstructor()));
   ASSERT(!completer_constructor.IsNull());
 
   // Add to AST:
   //   var :async_op;
   //   var :async_completer;
+  //   var :await_jump_var;
+  //   var :await_ctx_var;
   LocalVariable* async_op_var = new (I) LocalVariable(
       Scanner::kNoSourcePos,
       Symbols::AsyncOperation(),
       Type::ZoneHandle(I, Type::DynamicType()));
   current_block_->scope->AddVariable(async_op_var);
   found = closure_body->scope()->CaptureVariable(Symbols::AsyncOperation());
   ASSERT(found);
   LocalVariable* async_completer = new (I) LocalVariable(
       Scanner::kNoSourcePos,
       Symbols::AsyncCompleter(),
       Type::ZoneHandle(I, Type::DynamicType()));
   current_block_->scope->AddVariable(async_completer);
   found = closure_body->scope()->CaptureVariable(Symbols::AsyncCompleter());
   ASSERT(found);
+  LocalVariable* await_jump_var = new (I) LocalVariable(
+      Scanner::kNoSourcePos,
+      Symbols::AwaitJumpVar(),
+      Type::ZoneHandle(I, Type::DynamicType()));
+  current_block_->scope->AddVariable(await_jump_var);
+  found = closure_body->scope()->CaptureVariable(Symbols::AwaitJumpVar());
+  ASSERT(found);
+  LocalVariable* await_ctx_var = new (I) LocalVariable(
+      Scanner::kNoSourcePos,
+      Symbols::AwaitContextVar(),
+      Type::ZoneHandle(I, Type::DynamicType()));
+  current_block_->scope->AddVariable(await_ctx_var);
+  found = closure_body->scope()->CaptureVariable(Symbols::AwaitContextVar());
+  ASSERT(found);
 
   // Add to AST:
   //   :async_completer = new Completer();
-  ArgumentListNode* empty_args = new (I) ArgumentListNode(
-      Scanner::kNoSourcePos);
+  ArgumentListNode* empty_args =
+      new (I) ArgumentListNode(Scanner::kNoSourcePos);
   ConstructorCallNode* completer_constructor_node = new (I) ConstructorCallNode(
       Scanner::kNoSourcePos,
       TypeArguments::ZoneHandle(I),
       completer_constructor,
       empty_args);
   StoreLocalNode* store_completer = new (I) StoreLocalNode(
       Scanner::kNoSourcePos,
       async_completer,
       completer_constructor_node);
   current_block_->statements->Add(store_completer);
@@ skipping 30 matching lines @@
           Symbols::CompleterFuture()));
   current_block_->statements->Add(return_node);
   return CloseBlock();
 }
 
 
 void Parser::CloseAsyncClosure(SequenceNode* body) {
   TRACE_PARSER("CloseAsyncClosure");
   // We need a temporary expression to store intermediate return values.
   parsed_function()->EnsureExpressionTemp();
+  // Implicitly mark those variables below as captured. We currently mark all
+  // variables of all scopes as captured (below), but as soon as we do something
+  // smarter we rely on these internal variables to be available.
+  body->scope()->LookupVariable(Symbols::Completer(), false);
+  body->scope()->LookupVariable(Symbols::AwaitJumpVar(), false);
+  body->scope()->LookupVariable(Symbols::AwaitContextVar(), false);
+  body->scope()->RecursivelyCaptureAllVariables();
 }
 
 
 // Set up default values for all optional parameters to the function.
 void Parser::SetupDefaultsForOptionalParams(const ParamList* params,
                                             Array* default_values) {
   if (params->num_optional_parameters > 0) {
     // Build array of default parameter values.
     ParamDesc* param =
       params->parameters->data() + params->num_fixed_parameters;
@@ skipping 5653 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart