[promisehook] Implement PromiseHook

src/code-stub-assembler.cc

 // Copyright 2016 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/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 8224 matching lines @@
 }
 
 Node* CodeStubAssembler::IsDebugActive() {
   Node* is_debug_active = Load(
       MachineType::Uint8(),
       ExternalConstant(ExternalReference::debug_is_active_address(isolate())));
   return Word32NotEqual(is_debug_active, Int32Constant(0));
 }
 
 Node* CodeStubAssembler::IsPromiseHookEnabled() {
-  Node* const is_promisehook_enabled =
-      Load(MachineType::Uint8(),
-           ExternalConstant(
-               ExternalReference::is_promisehook_enabled_address(isolate())));
-  return Word32NotEqual(is_promisehook_enabled, Int32Constant(0));
+  Node* const promise_hook = Load(
+      MachineType::Uint8(),

[adamk, 2016/12/15 15:43:58]

Probably this needs to change now that it's a pointer instead of a bool. But as
a non-CSA-expert I'm not sure what the right way to change it is (in particular,
I'm curious how we deal with 32/64-bit pointers.

[gsathya, 2016/12/15 16:32:06]

Doh, ofc. Sorry for being sloppy!

+      ExternalConstant(ExternalReference::promise_hook_address(isolate())));
+  return Word32NotEqual(promise_hook, Int32Constant(0));
 }
 
 Node* CodeStubAssembler::AllocateJSPromise(Node* context) {
   Node* const native_context = LoadNativeContext(context);
   Node* const promise_fun =
       LoadContextElement(native_context, Context::PROMISE_FUNCTION_INDEX);
   Node* const initial_map =
       LoadObjectField(promise_fun, JSFunction::kPrototypeOrInitialMapOffset);
   Node* const instance = AllocateJSObjectFromMap(initial_map);
 
@@ skipping 29 matching lines @@
                        Heap::kUndefinedValueRootIndex);
   StoreObjectFieldRoot(result, PromiseReactionJobInfo::kDebugNameOffset,
                        Heap::kUndefinedValueRootIndex);
   StoreObjectFieldNoWriteBarrier(result, PromiseReactionJobInfo::kContextOffset,
                                  context);
   return result;
 }
 
 }  // namespace internal
 }  // namespace v8