Async/await Promise dependency graph

src/parsing/parser.cc

Index: src/parsing/parser.cc
diff --git a/src/parsing/parser.cc b/src/parsing/parser.cc
index 4973857c37ea0f2cf2854c35000be559db065e3a..2621150be01cea0cb1b427dd1e857532d1717687 100644
--- a/src/parsing/parser.cc
+++ b/src/parsing/parser.cc
@@ -4380,7 +4380,8 @@ Expression* Parser::ExpressionListToExpression(ZoneList<Expression*>* args) {
 Expression* Parser::RewriteAwaitExpression(Expression* value, int await_pos) {
   // yield do {
   //   tmp = <operand>;
-  //   tmp = %AsyncFunctionAwait(.generator_object, tmp);
+  //   tmp2 = .promise;
+  //   tmp = %AsyncFunctionAwait(.generator_object, tmp, tmp2);
   // }
   Variable* generator_object_variable =
       function_state_->generator_object_variable();
@@ -4400,12 +4401,23 @@ Expression* Parser::RewriteAwaitExpression(Expression* value, int await_pos) {
       factory()->NewExpressionStatement(value_assignment, value->position()),
       zone());
 
+  Variable* promise_temp_var =
+      NewTemporary(ast_value_factory()->empty_string());
+  Expression* promise_assignment = factory()->NewAssignment(
+      Token::ASSIGN, factory()->NewVariableProxy(promise_temp_var),
+      BuildDotPromise(), nopos);
+  do_block->statements()->Add(
+      factory()->NewExpressionStatement(promise_assignment, value->position()),
+      zone());

[Dan Ehrenberg, 2016/09/14 01:09:14]

This parser change should address the Blink failures. It preserves Yang's change
to ensure that the right debugging positions are present. PTAL.

[Dan Ehrenberg, 2016/09/14 01:32:38]

Sorry, issues still remaining; will work on more tomorrow.

+
   ZoneList<Expression*>* async_function_await_args =
-      new (zone()) ZoneList<Expression*>(2, zone());
+      new (zone()) ZoneList<Expression*>(3, zone());
   Expression* generator_object =
       factory()->NewVariableProxy(generator_object_variable);
   async_function_await_args->Add(generator_object, zone());
   async_function_await_args->Add(factory()->NewVariableProxy(temp_var), zone());
+  async_function_await_args->Add(factory()->NewVariableProxy(promise_temp_var),
+                                 zone());
 
   // The parser emits calls to AsyncFunctionAwaitCaught, but the
   // AstNumberingVisitor will rewrite this to AsyncFunctionAwaitUncaught