Bug 1002737 - Convert PropDesc::pd_ to a JSObject *. (r=jorendorff)

js/src/jsobj.cpp

@@ -268,7 +268,7 @@ js::NewPropertyDescriptorObject(JSContext *cx, Handle<PropertyDescriptor> desc,
     d.initFromPropertyDescriptor(desc);
     if (!d.makeObject(cx))
         return false;
-    vp.set(d.pd());
+    vp.set(d.descriptorValue());
     return true;
 }
 
@@ -276,7 +276,7 @@ void
 PropDesc::initFromPropertyDescriptor(Handle<PropertyDescriptor> desc)
 {
     isUndefined_ = false;
-    pd_.setUndefined();
+    descObj_ = nullptr;
     attrs = uint8_t(desc.attributes());
     JS_ASSERT_IF(attrs & JSPROP_READONLY, !(attrs & (JSPROP_GETTER | JSPROP_SETTER)));
     if (desc.hasGetterOrSetterObject()) {
@@ -333,7 +333,7 @@ PropDesc::makeObject(JSContext *cx)
         return false;
     }
 
-    pd_.setObject(*obj);
+    descObj_ = obj;
     return true;
 }
 
@@ -443,7 +443,7 @@ PropDesc::initialize(JSContext *cx, const Value &origval, bool checkAccessors)
     RootedObject desc(cx, &v.toObject());
 
     /* Make a copy of the descriptor. We might need it later. */
-    pd_ = v;
+    descObj_ = desc;
 
     isUndefined_ = false;
 
@@ -1048,7 +1048,7 @@ js::DefineProperty(JSContext *cx, HandleObject obj, HandleId id, const PropDesc
          * TrapDefineOwnProperty directly
          */
         if (obj->is<ProxyObject>()) {
-            RootedValue pd(cx, desc.pd());
+            RootedValue pd(cx, desc.descriptorValue());
             return Proxy::defineProperty(cx, obj, id, pd);
         }
         return Reject(cx, obj, JSMSG_OBJECT_NOT_EXTENSIBLE, throwError, rval);
@@ -1135,7 +1135,7 @@ js::DefineProperties(JSContext *cx, HandleObject obj, HandleObject props)
          */
         if (obj->is<ProxyObject>()) {
             for (size_t i = 0, len = ids.length(); i < len; i++) {
-                RootedValue pd(cx, descs[i].pd());
+                RootedValue pd(cx, descs[i].descriptorValue());
                 if (!Proxy::defineProperty(cx, obj, ids[i], pd))
                     return false;
             }

js/src/jsobjinlines.h

@@ -644,7 +644,7 @@ namespace js {
 
 PropDesc::PropDesc(const Value &getter, const Value &setter,
                    Enumerability enumerable, Configurability configurable)
-  : pd_(UndefinedValue()),
+  : descObj_(nullptr),
     value_(UndefinedValue()),
     get_(getter), set_(setter),
     attrs(JSPROP_GETTER | JSPROP_SETTER | JSPROP_SHARED |

js/src/jsproxy.cpp

@@ -1111,7 +1111,7 @@ FromGenericPropertyDescriptor(JSContext *cx, MutableHandle<PropDesc> desc, Mutab
     // steps 3-9
     if (!desc.makeObject(cx))
         return false;
-    rval.set(desc.pd());
+    rval.set(desc.descriptorValue());
     return true;
 }
 

js/src/vm/Debugger.cpp

@@ -5334,7 +5334,7 @@ DebuggerObject_defineProperty(JSContext *cx, unsigned argc, Value *vp)
     Rooted<PropDesc> desc(cx);
     if (!desc.initialize(cx, args[1], false))
         return false;
-    desc.clearPd();
+    desc.clearDescriptorObject();
 
     if (!dbg->unwrapPropDescInto(cx, obj, desc, &desc))
         return false;

js/src/vm/ObjectImpl.cpp

@@ -25,7 +25,7 @@ PropDesc::PropDesc()
 void
 PropDesc::setUndefined()
 {
-    pd_ = UndefinedValue();
+    descObj_ = nullptr;
     value_ = UndefinedValue();
     get_ = UndefinedValue();
     set_ = UndefinedValue();
@@ -333,7 +333,8 @@ js::ObjectImpl::markChildren(JSTracer *trc)
 void
 PropDesc::trace(JSTracer *trc)
 {
-    gc::MarkValueRoot(trc, &pd_, "PropDesc pd");
+    if (descObj_)
+        gc::MarkObjectRoot(trc, &descObj_, "PropDesc descriptor object");
     gc::MarkValueRoot(trc, &value_, "PropDesc value");
     gc::MarkValueRoot(trc, &get_, "PropDesc get");
     gc::MarkValueRoot(trc, &set_, "PropDesc set");

js/src/vm/PropDesc.h

@@ -34,7 +34,7 @@ struct PropDesc {
      * Original object from which this descriptor derives, passed through for
      * the benefit of proxies.
      */
-    Value pd_;
+    JSObject *descObj_;
 
     Value value_, get_, set_;
 
@@ -53,7 +53,7 @@ struct PropDesc {
     bool isUndefined_ : 1;
 
     explicit PropDesc(const Value &v)
-      : pd_(UndefinedValue()),
+      : descObj_(nullptr),
         value_(v),
         get_(UndefinedValue()), set_(UndefinedValue()),
         attrs(0),
@@ -80,7 +80,7 @@ struct PropDesc {
 
     PropDesc(const Value &v, Writability writable,
              Enumerability enumerable, Configurability configurable)
-      : pd_(UndefinedValue()),
+      : descObj_(nullptr),
         value_(v),
         get_(UndefinedValue()), set_(UndefinedValue()),
         attrs((writable ? 0 : JSPROP_READONLY) |
@@ -138,8 +138,11 @@ struct PropDesc {
     bool hasEnumerable() const { MOZ_ASSERT(!isUndefined()); return hasEnumerable_; }
     bool hasConfigurable() const { MOZ_ASSERT(!isUndefined()); return hasConfigurable_; }
 
-    Value pd() const { MOZ_ASSERT(!isUndefined()); return pd_; }
-    void clearPd() { pd_ = UndefinedValue(); }
+    Value descriptorValue() const {
+        MOZ_ASSERT(!isUndefined());
+        return descObj_ ? ObjectValue(*descObj_) : UndefinedValue();
+    }
+    void clearDescriptorObject() { descObj_ = nullptr; }
 
     uint8_t attributes() const { MOZ_ASSERT(!isUndefined()); return attrs; }
 
@@ -261,7 +264,7 @@ class PropDescOperations
     bool hasEnumerable() const { return desc()->hasEnumerable(); }
     bool hasConfigurable() const { return desc()->hasConfigurable(); }
 
-    Value pd() const { return desc()->pd(); }
+    Value descriptorValue() const { return desc()->descriptorValue(); }
 
     uint8_t attributes() const { return desc()->attributes(); }
 
@@ -321,7 +324,7 @@ class MutablePropDescOperations : public PropDescOperations<Outer>
     }
 
     void setUndefined() { desc()->setUndefined(); }
-    void clearPd() { desc()->clearPd(); }
+    void clearDescriptorObject() { desc()->clearDescriptorObject(); }
 };
 
 } /* namespace JS */
@@ -333,8 +336,7 @@ struct GCMethods<PropDesc> {
     static PropDesc initial() { return PropDesc(); }
     static ThingRootKind kind() { return THING_ROOT_PROP_DESC; }
     static bool poisoned(const PropDesc &desc) {
-        return (desc.pd_.isGCThing() &&
-                JS::IsPoisonedPtr(desc.pd_.toGCThing())) ||
+        return JS::IsPoisonedPtr(desc.descObj_) ||
                (desc.value_.isGCThing() &&
                 JS::IsPoisonedPtr(desc.value_.toGCThing())) ||
                (desc.get_.isGCThing() &&