First version of the new generators implementation.

src/builtins.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/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/once.h"
@@ skipping 2311 matching lines @@
 
 void Generate_GeneratorPrototypeResume(
     CodeStubAssembler* assembler, JSGeneratorObject::ResumeMode resume_mode,
     char const* const method_name) {
   typedef CodeStubAssembler::Label Label;
   typedef compiler::Node Node;
 
   Node* receiver = assembler->Parameter(0);
   Node* value = assembler->Parameter(1);
   Node* context = assembler->Parameter(4);
-  Node* zero = assembler->SmiConstant(Smi::FromInt(0));
+  Node* closed = assembler->SmiConstant(
+      Smi::FromInt(JSGeneratorObject::kGeneratorClosed));
 
   // Check if the {receiver} is actually a JSGeneratorObject.
   Label if_receiverisincompatible(assembler, Label::kDeferred);
   assembler->GotoIf(assembler->WordIsSmi(receiver), &if_receiverisincompatible);
   Node* receiver_instance_type = assembler->LoadInstanceType(receiver);
   assembler->GotoUnless(assembler->Word32Equal(
                             receiver_instance_type,
                             assembler->Int32Constant(JS_GENERATOR_OBJECT_TYPE)),
                         &if_receiverisincompatible);
 
   // Check if the {receiver} is running or already closed.
   Node* receiver_continuation = assembler->LoadObjectField(
       receiver, JSGeneratorObject::kContinuationOffset);
   Label if_receiverisclosed(assembler, Label::kDeferred),
       if_receiverisrunning(assembler, Label::kDeferred);
-  assembler->GotoIf(assembler->SmiEqual(receiver_continuation, zero),
+  assembler->GotoIf(assembler->SmiEqual(receiver_continuation, closed),
                     &if_receiverisclosed);
-  assembler->GotoIf(assembler->SmiLessThan(receiver_continuation, zero),
+  DCHECK_LT(JSGeneratorObject::kGeneratorExecuting,
+            JSGeneratorObject::kGeneratorClosed);
+  assembler->GotoIf(assembler->SmiLessThan(receiver_continuation, closed),
                     &if_receiverisrunning);
 
   // Resume the {receiver} using our trampoline.
   Node* result = assembler->CallStub(
       CodeFactory::ResumeGenerator(assembler->isolate()), context, value,
       receiver, assembler->SmiConstant(Smi::FromInt(resume_mode)));
   assembler->Return(result);
 
   assembler->Bind(&if_receiverisincompatible);
   {
@@ skipping 2938 matching lines @@
 BUILTIN_LIST_T(DEFINE_BUILTIN_ACCESSOR_T)
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8