First version of the new generators implementation.

src/runtime/runtime-generator.cc

Index: src/runtime/runtime-generator.cc
diff --git a/src/runtime/runtime-generator.cc b/src/runtime/runtime-generator.cc
index eeac3ad6b64b934b897387313139d88ccaa6eb4e..a9bcb425627d5c4ee9e56c4779c17cfdfa2503b4 100644
--- a/src/runtime/runtime-generator.cc
+++ b/src/runtime/runtime-generator.cc
@@ -68,6 +68,7 @@ RUNTIME_FUNCTION(Runtime_SuspendJSGeneratorObject) {
   return isolate->heap()->undefined_value();
 }
 
+
 RUNTIME_FUNCTION(Runtime_GeneratorClose) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
@@ -109,6 +110,16 @@ RUNTIME_FUNCTION(Runtime_GeneratorGetInput) {
 }
 
 
+// Returns resume mode of generator activation.
+RUNTIME_FUNCTION(Runtime_GeneratorGetResumeMode) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);
+
+  return Smi::FromInt(generator->resume_mode());
+}
+
+
 // Returns generator continuation as a PC offset, or the magic -1 or 0 values.
 RUNTIME_FUNCTION(Runtime_GeneratorGetContinuation) {
   HandleScope scope(isolate);
@@ -134,5 +145,60 @@ RUNTIME_FUNCTION(Runtime_GeneratorGetSourcePosition) {
   return isolate->heap()->undefined_value();
 }
 
+
+RUNTIME_FUNCTION(Runtime_SuspendIgnitionGenerator) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Smi, state, 1);
+
+  JavaScriptFrameIterator it(isolate);
+  JavaScriptFrame* frame = it.frame();
+  Handle<JSFunction> function(frame->function());
+  CHECK(function->shared()->is_generator());
+  CHECK(frame->type() == StackFrame::INTERPRETED);

[Michael Starzinger, 2016/04/15 14:13:47]

nit: CHECK_EQ

[neis, 2016/04/18 08:04:17]

Done.

+
+  // Save register file.
+  int size = function->shared()->bytecode_array()->register_count();
+  Handle<FixedArray> register_file = isolate->factory()->NewFixedArray(size);
+  for (int i = 0; i < size; ++i) {
+    Object* value =
+        static_cast<InterpretedFrame*>(frame)->ReadInterpreterRegister(i);
+    register_file->set(i, value);
+  }
+
+  generator->set_operand_stack(*register_file);
+  generator->set_context(Context::cast(frame->context()));
+  generator->set_continuation(state->value() + 1);  // continuation 0 is special

[rmcilroy, 2016/04/15 13:17:46]

Is continuation '0' only special in the FCG generator implementation, or is it
special for the Ignition version too? If the former, could you add a TODO to
avoid this offsetting by 1 once the FCG implementation disappears.

[neis, 2016/04/18 08:04:17]

Both actually, because of some shared code.  But I changed that code now so that
0 is no longer special, and got rid of the +1/-1 here.

+
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_ResumeIgnitionGenerator) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);
+
+  JavaScriptFrameIterator it(isolate);
+  JavaScriptFrame* frame = it.frame();
+  Handle<JSFunction> function(frame->function());
+  CHECK(function->shared()->is_generator());
+  CHECK(frame->type() == StackFrame::INTERPRETED);

[Michael Starzinger, 2016/04/15 14:13:47]

nit: CHECK_EQ

[neis, 2016/04/18 08:04:17]

Done.

+
+  // Restore register file.
+  int size = function->shared()->bytecode_array()->register_count();
+  DCHECK_EQ(size, generator->operand_stack()->length());
+  for (int i = 0; i < size; ++i) {
+    Object* value = generator->operand_stack()->get(i);
+    static_cast<InterpretedFrame*>(frame)->WriteInterpreterRegister(i, value);
+  }
+  generator->set_operand_stack(isolate->heap()->empty_fixed_array());
+
+  int state = generator->continuation() - 1;
+  generator->set_continuation(JSGeneratorObject::kGeneratorExecuting);
+  return Smi::FromInt(state);
+}
+
 }  // namespace internal
 }  // namespace v8