Merged: Allow embedder to set promise internal field count

Revision: 6803eef

BUG=v8:6435
LOG=N
NOTRY=true
NOPRESUBMIT=true
NOTREECHECKS=true
[email protected], [email protected]

Change-Id: I36d1c19324f51dde6356a8db2383036cc5f77c24
Reviewed-on: https://chromium-review.googlesource.com/523006
Reviewed-by: Adam Klein <[email protected]>
Commit-Queue: Ali Ijaz Sheikh <[email protected]>
Cr-Commit-Position: refs/branch-heads/5.9@{crosswalk-project#67}
Cr-Branched-From: fe9bb7e-refs/heads/5.9.211@{crosswalk-project#1}
Cr-Branched-From: 70ad237-refs/heads/master@{#44591}

BUILD.gn

@@ -44,6 +44,9 @@ declare_args() {
   # Sets -dENABLE_DISASSEMBLER.
   v8_enable_disassembler = ""
 
+  # Sets the number of internal fields on promise objects.
+  v8_promise_internal_field_count = 0
+
   # Sets -dENABLE_GDB_JIT_INTERFACE.
   v8_enable_gdbjit = ""
 
@@ -218,6 +221,10 @@ config("features") {
   if (v8_enable_disassembler) {
     defines += [ "ENABLE_DISASSEMBLER" ]
   }
+  if (v8_promise_internal_field_count != 0) {
+    defines +=
+        [ "V8_PROMISE_INTERNAL_FIELD_COUNT=${v8_promise_internal_field_count}" ]
+  }
   if (v8_enable_future) {
     defines += [ "V8_ENABLE_FUTURE" ]
   }

gypfiles/features.gypi

@@ -31,6 +31,8 @@
   'variables': {
     'v8_enable_disassembler%': 0,
 
+    'v8_promise_internal_field_count%': 0,
+
     'v8_enable_gdbjit%': 0,
 
     'v8_enable_verify_csa%': 0,
@@ -77,6 +79,9 @@
       ['v8_enable_disassembler==1', {
         'defines': ['ENABLE_DISASSEMBLER',],
       }],
+      ['v8_promise_internal_field_count!=0', {
+        'defines': ['V8_PROMISE_INTERNAL_FIELD_COUNT','v8_promise_internal_field_count'],
+      }],
       ['v8_enable_gdbjit==1', {
         'defines': ['ENABLE_GDB_JIT_INTERFACE',],
       }],

include/v8.h

@@ -3823,6 +3823,10 @@ class V8_EXPORT Function : public Object {
   static void CheckCast(Value* obj);
 };
 
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
 
 /**
  * An instance of the built-in Promise constructor (ES6 draft).
@@ -3904,6 +3908,8 @@ class V8_EXPORT Promise : public Object {
 
   V8_INLINE static Promise* Cast(Value* obj);
 
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
  private:
   Promise();
   static void CheckCast(Value* obj);

src/bootstrapper.cc

@@ -2088,9 +2088,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
   {  // -- P r o m i s e
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), TENURED);
-    Handle<JSFunction> promise_fun =
-        InstallFunction(global, "Promise", JS_PROMISE_TYPE, JSPromise::kSize,
-                        prototype, Builtins::kPromiseConstructor);
+    Handle<JSFunction> promise_fun = InstallFunction(
+        global, "Promise", JS_PROMISE_TYPE, JSPromise::kSizeWithEmbedderFields,
+        prototype, Builtins::kPromiseConstructor);
     InstallWithIntrinsicDefaultProto(isolate, promise_fun,
                                      Context::PROMISE_FUNCTION_INDEX);
 

src/builtins/builtins-promise-gen.cc

@@ -31,6 +31,10 @@ void PromiseBuiltinsAssembler::PromiseInit(Node* promise) {
                                  SmiConstant(v8::Promise::kPending));
   StoreObjectFieldNoWriteBarrier(promise, JSPromise::kFlagsOffset,
                                  SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(promise, offset, SmiConstant(Smi::kZero));
+  }
 }
 
 Node* PromiseBuiltinsAssembler::AllocateAndInitJSPromise(Node* context) {
@@ -62,6 +66,10 @@ Node* PromiseBuiltinsAssembler::AllocateAndSetJSPromise(Node* context,
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kResultOffset, result);
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kFlagsOffset,
                                  SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(instance, offset, SmiConstant(Smi::kZero));
+  }
 
   Label out(this);
   GotoIfNot(IsPromiseHookEnabledOrDebugIsActive(), &out);

src/factory.cc

@@ -927,6 +927,9 @@ Handle<JSPromise> Factory::NewJSPromise() {
   Handle<JSPromise> promise = Handle<JSPromise>::cast(promise_obj);
   promise->set_status(v8::Promise::kPending);
   promise->set_flags(0);
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    promise->SetEmbedderField(i, Smi::kZero);
+  }
 
   isolate()->RunPromiseHook(PromiseHookType::kInit, promise, undefined_value());
   return promise;

src/objects.h

@@ -7339,6 +7339,8 @@ class JSPromise : public JSObject {
       kFulfillReactionsOffset + kPointerSize;
   static const int kFlagsOffset = kRejectReactionsOffset + kPointerSize;
   static const int kSize = kFlagsOffset + kPointerSize;
+  static const int kSizeWithEmbedderFields =
+      kSize + v8::Promise::kEmbedderFieldCount * kPointerSize;
 
   // Flags layout.
   static const int kHasHandlerBit = 0;