new style of property/function callbacks

src/x64/macro-assembler-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 674 matching lines @@
 
   // rcx must be used to pass the pointer to the return value slot.
   lea(rcx, StackSpaceOperand(arg_stack_space));
 #else
   EnterApiExitFrame(arg_stack_space);
 #endif
 }
 
 
 void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
-                                              int stack_space) {
-  Label empty_result;
+                                              int stack_space,
+                                              int return_value_offset) {
   Label prologue;
   Label promote_scheduled_exception;
   Label delete_allocated_handles;
   Label leave_exit_frame;
   Label write_back;
 
   Factory* factory = isolate()->factory();
   ExternalReference next_address =
       ExternalReference::handle_scope_next_address(isolate());
   const int kNextOffset = 0;
@@ skipping 31 matching lines @@
 
   if (FLAG_log_timer_events) {
     FrameScope frame(this, StackFrame::MANUAL);
     PushSafepointRegisters();
     PrepareCallCFunction(1);
     LoadAddress(arg_reg_1, ExternalReference::isolate_address(isolate()));
     CallCFunction(ExternalReference::log_leave_external_function(isolate()), 1);
     PopSafepointRegisters();
   }
 
+  // Can skip the result check for new-style callbacks
+  // TODO(dcarney): may need to pass this information down
+  // as some function_addresses might not have been registered
+  if (!CallbackTable::ReturnsVoid(isolate(), function_address)) {
+    Label empty_result;
 #if defined(_WIN64) && !defined(__MINGW64__)
-  // rax keeps a pointer to v8::Handle, unpack it.
-  movq(rax, Operand(rax, 0));
+    // rax keeps a pointer to v8::Handle, unpack it.
+    movq(rax, Operand(rax, 0));
 #endif
-  // Check if the result handle holds 0.
-  testq(rax, rax);
-  j(zero, &empty_result);
-  // It was non-zero.  Dereference to get the result value.
-  movq(rax, Operand(rax, 0));
+    // Check if the result handle holds 0.
+    testq(rax, rax);
+    j(zero, &empty_result);
+    // It was non-zero.  Dereference to get the result value.
+    movq(rax, Operand(rax, 0));
+    jmp(&prologue);
+    bind(&empty_result);
+  }
+  // Load the value from ReturnValue
+  movq(rax, StackSpaceOperand(0));
+  movq(rax, Operand(rax, return_value_offset * kPointerSize));
   bind(&prologue);
 
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   subl(Operand(base_reg, kLevelOffset), Immediate(1));
   movq(Operand(base_reg, kNextOffset), prev_next_address_reg);
   cmpq(prev_limit_reg, Operand(base_reg, kLimitOffset));
   j(not_equal, &delete_allocated_handles);
   bind(&leave_exit_frame);
 
@@ skipping 33 matching lines @@
   j(equal, &ok, Label::kNear);
 
   Abort("API call returned invalid object");
 
   bind(&ok);
 #endif
 
   LeaveApiExitFrame();
   ret(stack_space * kPointerSize);
 
-  bind(&empty_result);
-  // It was zero; the result is undefined.
-  LoadRoot(rax, Heap::kUndefinedValueRootIndex);
-  jmp(&prologue);
-
   bind(&promote_scheduled_exception);
   TailCallRuntime(Runtime::kPromoteScheduledException, 0, 1);
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);
   movq(Operand(base_reg, kLimitOffset), prev_limit_reg);
   movq(prev_limit_reg, rax);
   LoadAddress(arg_reg_1, ExternalReference::isolate_address(isolate()));
   LoadAddress(rax,
               ExternalReference::delete_handle_scope_extensions(isolate()));
@@ skipping 3810 matching lines @@
   j(greater, &no_info_available);
   CompareRoot(MemOperand(scratch_reg, -AllocationSiteInfo::kSize),
               Heap::kAllocationSiteInfoMapRootIndex);
   bind(&no_info_available);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64