Async/await Promise dependency graph

src/parsing/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/parsing/parser.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/ast/ast-expression-rewriter.h"
@@ skipping 4533 matching lines @@
     expr = factory()->NewBinaryOperation(Token::COMMA, expr, args->at(i),
                                          expr->position());
   }
   return expr;
 }
 
 Expression* Parser::RewriteAwaitExpression(Expression* value, int await_pos) {
   // yield do {
   //   promise_tmp = .promise;
   //   tmp = <operand>;
-  //   %AsyncFunctionAwait(.generator_object, tmp);
+  //   %AsyncFunctionAwait(.generator_object, tmp, promise_tmp);
   //   promise_tmp
   // }
   // The value of the expression is returned to the caller of the async
   // function for the first yield statement; for this, .promise is the
   // appropriate return value, being a Promise that will be fulfilled or
   // rejected with the appropriate value by the desugaring. Subsequent yield
   // occurrences will return to the AsyncFunctionNext call within the
   // implemementation of the intermediate throwaway Promise's then handler.
   // This handler has nothing useful to do with the value, as the Promise is
   // ignored. If we yielded the value of the throwawayPromise that
@@ skipping 24 matching lines @@
 
   // Wrap value evaluation to provide a break location.
   Variable* temp_var = NewTemporary(ast_value_factory()->empty_string());
   Expression* value_assignment = factory()->NewAssignment(
       Token::ASSIGN, factory()->NewVariableProxy(temp_var), value, nopos);
   do_block->statements()->Add(
       factory()->NewExpressionStatement(value_assignment, value->position()),
       zone());
 
   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
   // if there is no local enclosing try/catch block.
   Expression* async_function_await =
       factory()->NewCallRuntime(Context::ASYNC_FUNCTION_AWAIT_CAUGHT_INDEX,
                                 async_function_await_args, nopos);
   do_block->statements()->Add(
       factory()->NewExpressionStatement(async_function_await, await_pos),
       zone());
@@ skipping 1207 matching lines @@
   node->Print(Isolate::Current());
 }
 #endif  // DEBUG
 
 #undef CHECK_OK
 #undef CHECK_OK_VOID
 #undef CHECK_FAILED
 
 }  // namespace internal
 }  // namespace v8