Revert D19318820: Make direct property slots trailing and overlapping…

… w/ C++ fields of subclasses

Differential Revision:
D19318820

Original commit changeset: 516617e461c1

fbshipit-source-id: 400652cbfdd0995672f3fa4653b9493af765c23b

include/hermes/VM/Callable.h

@@ -141,10 +141,7 @@ class Callable : public JSObject {
   /// Fast constructor used by deserializer.
   Callable(Deserializer &d, const VTable *vt);
 
-  friend void serializeCallableImpl(
-      Serializer &s,
-      const GCCell *cell,
-      unsigned overlapSlots);
+  friend void serializeCallableImpl(Serializer &s, const GCCell *cell);
 #endif
 
   static bool classof(const GCCell *cell) {
@@ -360,6 +357,10 @@ class BoundFunction final : public Callable {
   using Super = Callable;
   static CallableVTable vt;
 
+  // We need one more slot for '.length'
+  static const PropStorage::size_type NAMED_PROPERTY_SLOTS =
+      Super::NAMED_PROPERTY_SLOTS + 1;
+
   static bool classof(const GCCell *cell) {
     return cell->getKind() == CellKind::BoundFunctionKind;
   }
@@ -465,16 +466,17 @@ class NativeFunction : public Callable {
       void *context,
       NativeFunctionPtr functionPtr);
 
-  static void serializeNativeFunctionImpl(
-      Serializer &s,
-      const GCCell *cell,
-      unsigned overlapSlots);
+  static void serializeNativeFunctionImpl(Serializer &s, const GCCell *cell);
   friend void NativeFunctionSerialize(Serializer &s, const GCCell *cell);
 #endif
 
   using Super = Callable;
   static CallableVTable vt;
 
+  // We need two more slots for '.name' and '.length'
+  static const PropStorage::size_type NAMED_PROPERTY_SLOTS =
+      Super::NAMED_PROPERTY_SLOTS + 2;
+
   static bool classof(const GCCell *cell) {
     return kindInRange(
         cell->getKind(),
@@ -644,9 +646,7 @@ class NativeFunction : public Callable {
       Runtime *runtime,
       unsigned index) {
     return JSObject::getInternalProperty(
-        self,
-        runtime,
-        numOverlapSlots<NativeFunction>() + ANONYMOUS_PROPERTY_SLOTS + index);
+        self, runtime, ANONYMOUS_PROPERTY_SLOTS + index);
   }
 
   /// Set the value in an additional slot.
@@ -658,10 +658,7 @@ class NativeFunction : public Callable {
       unsigned index,
       HermesValue value) {
     return JSObject::setInternalProperty(
-        self,
-        runtime,
-        numOverlapSlots<NativeFunction>() + ANONYMOUS_PROPERTY_SLOTS + index,
-        value);
+        self, runtime, ANONYMOUS_PROPERTY_SLOTS + index, value);
   }
 
  protected:
@@ -742,8 +739,7 @@ class NativeConstructor final : public NativeFunction {
         runtime,
         *parentHandle,
         runtime->getHiddenClassForPrototypeRaw(
-            *parentHandle,
-            numOverlapSlots<NativeConstructor>() + ANONYMOUS_PROPERTY_SLOTS),
+            *parentHandle, ANONYMOUS_PROPERTY_SLOTS),
         context,
         functionPtr,
         creator,
@@ -768,8 +764,7 @@ class NativeConstructor final : public NativeFunction {
         runtime,
         *parentHandle,
         runtime->getHiddenClassForPrototypeRaw(
-            *parentHandle,
-            numOverlapSlots<NativeConstructor>() + ANONYMOUS_PROPERTY_SLOTS),
+            *parentHandle, ANONYMOUS_PROPERTY_SLOTS),
         parentEnvHandle,
         context,
         functionPtr,
@@ -866,10 +861,7 @@ class JSFunction : public Callable {
 #ifdef HERMESVM_SERIALIZE
   JSFunction(Deserializer &d, const VTable *vt);
 
-  friend void serializeFunctionImpl(
-      Serializer &s,
-      const GCCell *cell,
-      unsigned overlapSlots);
+  friend void serializeFunctionImpl(Serializer &s, const GCCell *cell);
   friend void FunctionDeserialize(Deserializer &d, CellKind kind);
 #endif
 
@@ -908,6 +900,10 @@ class JSFunction : public Callable {
  public:
   static CallableVTable vt;
 
+  // We need two more slot for '.length' and '.prototype'
+  static const PropStorage::size_type NAMED_PROPERTY_SLOTS =
+      Super::NAMED_PROPERTY_SLOTS + 2;
+
   static bool classof(const GCCell *cell) {
     return kindInRange(
         cell->getKind(),

include/hermes/VM/Domain.h

@@ -258,14 +258,6 @@ class RequireContext final : public JSObject {
   static const PropStorage::size_type ANONYMOUS_PROPERTY_SLOTS =
       Super::ANONYMOUS_PROPERTY_SLOTS + 2;
 
-  static constexpr SlotIndex domainPropIndex() {
-    return numOverlapSlots<RequireContext>() + ANONYMOUS_PROPERTY_SLOTS - 2;
-  }
-
-  static constexpr SlotIndex dirnamePropIndex() {
-    return numOverlapSlots<RequireContext>() + ANONYMOUS_PROPERTY_SLOTS - 1;
-  }
-
   static bool classof(const GCCell *cell) {
     return cell->getKind() == CellKind::RequireContextKind;
   }
@@ -278,14 +270,13 @@ class RequireContext final : public JSObject {
 
   /// \return the domain for this require context.
   static Domain *getDomain(Runtime *runtime, RequireContext *self) {
-    return vmcast<Domain>(
-        JSObject::getInternalProperty(self, runtime, domainPropIndex()));
+    return vmcast<Domain>(JSObject::getInternalProperty(self, runtime, 0));
   }
 
   /// \return the current dirname for this require context.
   static StringPrimitive *getDirname(Runtime *runtime, RequireContext *self) {
     return vmcast<StringPrimitive>(
-        JSObject::getInternalProperty(self, runtime, dirnamePropIndex()));
+        JSObject::getInternalProperty(self, runtime, 1));
   }
 
  private:

include/hermes/VM/JSArray.h

@@ -24,8 +24,7 @@ class ArrayImpl : public JSObject {
 #ifdef HERMESVM_SERIALIZE
   ArrayImpl(Deserializer &d, const VTable *vt);
 
-  friend void
-  serializeArrayImpl(Serializer &s, const GCCell *cell, unsigned overlapSlots);
+  friend void serializeArrayImpl(Serializer &s, const GCCell *cell);
 #endif
 
   static bool classof(const GCCell *cell) {
@@ -364,14 +363,7 @@ class JSArray final : public ArrayImpl {
   // Object needs to be able to call setLength.
   friend class JSObject;
 
-  static constexpr SlotIndex jsArrayPropertyCount() {
-    return numOverlapSlots<JSArray>() + ANONYMOUS_PROPERTY_SLOTS +
-        NAMED_PROPERTY_SLOTS;
-  }
-
-  static constexpr inline SlotIndex lengthPropIndex() {
-    return jsArrayPropertyCount() - 1;
-  }
+  enum : SlotIndex { LengthPropIndex = 0, JSArrayPropertyCount = 1 };
 
   /// A copy of the ".length" property. We compare every putComputed()
   /// index against ".length", and extracting it from property storage every
@@ -397,7 +389,7 @@ class JSArray final : public ArrayImpl {
   static void putLength(JSArray *self, Runtime *runtime, uint32_t newLength) {
     self->shadowLength_ = newLength;
 
-    namedSlotRef(self, runtime, lengthPropIndex())
+    namedSlotRef(self, runtime, LengthPropIndex)
         .setNonPtr(HermesValue::encodeNumberValue(newLength));
   }
 

include/hermes/VM/JSDate.h

@@ -40,14 +40,14 @@ class JSDate final : public JSObject {
   /// \return the [[PrimitiveValue]] internal property.
   static HermesValue getPrimitiveValue(JSObject *self, Runtime *runtime) {
     return JSObject::getInternalProperty(
-        self, runtime, JSDate::primitiveValuePropIndex());
+        self, runtime, JSDate::primitiveValueIndex);
   }
 
   /// Set the [[PrimitiveValue]] internal property.
   static void
   setPrimitiveValue(JSObject *self, Runtime *runtime, HermesValue value) {
     return JSObject::setInternalProperty(
-        self, runtime, JSDate::primitiveValuePropIndex(), value);
+        self, runtime, JSDate::primitiveValueIndex, value);
   }
 
  protected:
@@ -61,9 +61,7 @@ class JSDate final : public JSObject {
       : JSObject(runtime, &vt.base, parent, clazz) {}
 
  protected:
-  static constexpr SlotIndex primitiveValuePropIndex() {
-    return numOverlapSlots<JSDate>() + ANONYMOUS_PROPERTY_SLOTS - 1;
-  }
+  static const SlotIndex primitiveValueIndex = ANONYMOUS_PROPERTY_SLOTS - 1;
 };
 
 } // namespace vm

include/hermes/VM/JSError.h

@@ -54,6 +54,9 @@ class JSError final : public JSObject {
     return cell->getKind() == CellKind::ErrorKind;
   }
 
+  static const PropStorage::size_type NAMED_PROPERTY_SLOTS =
+      Super::NAMED_PROPERTY_SLOTS + 1;
+
   /// Create an Error Object.
   static CallResult<HermesValue> create(
       Runtime *runtime,