Throw a TypeError when calling "next" method of a newly created generator with a value

src/x64/full-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1956 matching lines @@
       __ jmp(&suspend);
 
       __ bind(&continuation);
       __ jmp(&resume);
 
       __ bind(&suspend);
       VisitForAccumulatorValue(expr->generator_object());
       ASSERT(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ Move(FieldOperand(rax, JSGeneratorObject::kContinuationOffset),
               Smi::FromInt(continuation.pos()));
+      if (expr->yield_kind() == Yield::INITIAL) {
+        __ Move(FieldOperand(rax, JSGeneratorObject::kSuspendedStartOffset),
+                Smi::FromInt(continuation.pos()));
+      }
       __ movq(FieldOperand(rax, JSGeneratorObject::kContextOffset), rsi);
       __ movq(rcx, rsi);
       __ RecordWriteField(rax, JSGeneratorObject::kContextOffset, rcx, rdx,
                           kDontSaveFPRegs);
       __ lea(rbx, Operand(rbp, StandardFrameConstants::kExpressionsOffset));
       __ cmpq(rsp, rbx);
       __ j(equal, &post_runtime);
       __ push(rax);  // generator object
       __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
       __ movq(context_register(),
@@ skipping 112 matching lines @@
     JSGeneratorObject::ResumeMode resume_mode) {
   // The value stays in rax, and is ultimately read by the resumed generator, as
   // if the CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. Or it
   // is read to throw the value when the resumed generator is already closed.
   // rbx will hold the generator object until the activation has been resumed.
   VisitForStackValue(generator);
   VisitForAccumulatorValue(value);
   __ pop(rbx);
 
   // Check generator state.
-  Label wrong_state, closed_state, done;
+  Label wrong_state, closed_state, suspended_start_state, resume_state, done;
   STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting < 0);
   STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed == 0);
-  __ SmiCompare(FieldOperand(rbx, JSGeneratorObject::kContinuationOffset),
-                Smi::FromInt(0));
+  __ movq(rcx, FieldOperand(rbx, JSGeneratorObject::kContinuationOffset));
+  __ SmiCompare(rcx, Smi::FromInt(0));
   __ j(equal, &closed_state);
   __ j(less, &wrong_state);
+  __ cmpq(rcx, FieldOperand(rbx, JSGeneratorObject::kSuspendedStartOffset));
+  __ j(equal, &suspended_start_state);
+
+  __ bind(&resume_state);
 
   // Load suspended function and context.
   __ movq(rsi, FieldOperand(rbx, JSGeneratorObject::kContextOffset));
   __ movq(rdi, FieldOperand(rbx, JSGeneratorObject::kFunctionOffset));
 
   // Push receiver.
   __ push(FieldOperand(rbx, JSGeneratorObject::kReceiverOffset));
 
   // Push holes for arguments to generator function.
   __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
@@ skipping 50 matching lines @@
   __ push(rcx);
   __ jmp(&push_operand_holes);
   __ bind(&call_resume);
   __ push(rbx);
   __ push(result_register());
   __ Push(Smi::FromInt(resume_mode));
   __ CallRuntime(Runtime::kResumeJSGeneratorObject, 3);
   // Not reached: the runtime call returns elsewhere.
   __ Abort(kGeneratorFailedToResume);
 
+  // Throw the provided value.
+  Label throw_provided_value;
+  __ bind(&throw_provided_value);
+  if (resume_mode != JSGeneratorObject::NEXT) {
+    __ push(rax);
+    __ CallRuntime(Runtime::kThrow, 1);
+    __ jmp(&done);
+  }
+
+  // Reach here when calling initial resume to a generator.
+  __ bind(&suspended_start_state);
+  if (resume_mode == JSGeneratorObject::NEXT) {
+    // When value is provided and it is not undefined, throw error.
+    __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
+    __ j(equal, &resume_state);
+    __ CallRuntime(Runtime::kThrowGeneratorStartError, 0);
+    __ jmp(&done);
+  } else {
+    // Make generator's state to "closed".
+    __ Move(FieldOperand(rbx, JSGeneratorObject::kContinuationOffset),
+            Smi::FromInt(JSGeneratorObject::kGeneratorClosed));
+    __ jmp(&throw_provided_value);
+  }
+
   // Reach here when generator is closed.
   __ bind(&closed_state);
   if (resume_mode == JSGeneratorObject::NEXT) {
     // Return completed iterator result when generator is closed.
     __ PushRoot(Heap::kUndefinedValueRootIndex);
     // Pop value from top-of-stack slot; box result into result register.
     EmitCreateIteratorResult(true);
+    __ jmp(&done);
   } else {
-    // Throw the provided value.
-    __ push(rax);
-    __ CallRuntime(Runtime::kThrow, 1);
+    __ jmp(&throw_provided_value);
   }
-  __ jmp(&done);
 
   // Throw error if we attempt to operate on a running generator.
   __ bind(&wrong_state);
   __ push(rbx);
   __ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
 
   __ bind(&done);
   context()->Plug(result_register());
 }
 
@@ skipping 2688 matching lines @@
 
   ASSERT_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64