Desugar async/await to create the resulting Promise upfront

src/full-codegen/full-codegen.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/full-codegen/full-codegen.h"
 
 #include "src/ast/ast-numbering.h"
 #include "src/ast/ast.h"
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopes.h"
@@ skipping 901 matching lines @@
 
 void FullCodeGenerator::EmitContinue(Statement* target) {
   NestedStatement* current = nesting_stack_;
   int context_length = 0;
   // When continuing, we clobber the unpredictable value in the accumulator
   // with one that's safe for GC.  If we hit an exit from the try block of
   // try...finally on our way out, we will unconditionally preserve the
   // accumulator on the stack.
   ClearAccumulator();
   while (!current->IsContinueTarget(target)) {
+    if (HasStackOverflow()) return;
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred continue through finally");
       current->Exit(&context_length);
       DCHECK_EQ(-1, context_length);
       current->AsTryFinally()->deferred_commands()->RecordContinue(target);
       return;
     }
     current = current->Exit(&context_length);
   }
   int stack_depth = current->GetStackDepthAtTarget();
@@ skipping 20 matching lines @@
 
 void FullCodeGenerator::EmitBreak(Statement* target) {
   NestedStatement* current = nesting_stack_;
   int context_length = 0;
   // When breaking, we clobber the unpredictable value in the accumulator
   // with one that's safe for GC.  If we hit an exit from the try block of
   // try...finally on our way out, we will unconditionally preserve the
   // accumulator on the stack.
   ClearAccumulator();
   while (!current->IsBreakTarget(target)) {
+    if (HasStackOverflow()) return;
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred break through finally");
       current->Exit(&context_length);
       DCHECK_EQ(-1, context_length);
       current->AsTryFinally()->deferred_commands()->RecordBreak(target);
       return;
     }
     current = current->Exit(&context_length);
   }
   int stack_depth = current->GetStackDepthAtTarget();
@@ skipping 15 matching lines @@
 void FullCodeGenerator::VisitBreakStatement(BreakStatement* stmt) {
   Comment cmnt(masm_, "[ BreakStatement");
   SetStatementPosition(stmt);
   EmitBreak(stmt->target());
 }
 
 void FullCodeGenerator::EmitUnwindAndReturn() {
   NestedStatement* current = nesting_stack_;
   int context_length = 0;
   while (current != NULL) {
+    if (HasStackOverflow()) return;
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred return through finally");
       current->Exit(&context_length);
       DCHECK_EQ(-1, context_length);
       current->AsTryFinally()->deferred_commands()->RecordReturn();
       return;
     }
     current = current->Exit(&context_length);
   }
   EmitReturnSequence();
@@ skipping 954 matching lines @@
   return var->scope()->is_nonlinear() ||
          var->initializer_position() >= proxy->position();
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8