Bug 978238 - Part 1: Clean up PropDesc<->PropertyDescriptor conversions. (r=jorendorff)

js/src/jsobj.cpp

@@ -277,6 +277,9 @@ PropDesc::initFromPropertyDescriptor(Handle<PropertyDescriptor> desc)
 {
     MOZ_ASSERT(isUndefined());
 
+    if (!desc.object())
+        return;
+
     isUndefined_ = false;
     descObj_ = nullptr;
     attrs = uint8_t(desc.attributes());
@@ -306,6 +309,21 @@ PropDesc::initFromPropertyDescriptor(Handle<PropertyDescriptor> desc)
     hasConfigurable_ = true;
 }
 
+void
+PropDesc::populatePropertyDescriptor(HandleObject obj, MutableHandle<PropertyDescriptor> desc) const
+{
+    if (isUndefined()) {
+        desc.object().set(nullptr);
+        return;
+    }
+
+    desc.value().set(hasValue() ? value() : UndefinedValue());
+    desc.setGetter(getter());
+    desc.setSetter(setter());
+    desc.setAttributes(attributes());
+    desc.object().set(obj);
+}
+
 bool
 PropDesc::makeObject(JSContext *cx)
 {

js/src/jsproxy.cpp

@@ -683,11 +683,7 @@ ParsePropertyDescriptorObject(JSContext *cx, HandleObject obj, const Value &v,
         return false;
     if (complete)
         d.complete();
-    desc.object().set(obj);
+    d.populatePropertyDescriptor(obj, desc);
-    desc.value().set(d.hasValue() ? d.value() : UndefinedValue());
-    desc.setAttributes(d.attributes());
-    desc.setGetter(d.getter());
-    desc.setSetter(d.setter());
     return true;
 }
 

js/src/vm/PropDesc.h

@@ -125,6 +125,7 @@ struct PropDesc {
      * new property descriptor JSObject and defining properties on it.
      */
     void initFromPropertyDescriptor(Handle<JSPropertyDescriptor> desc);
+    void populatePropertyDescriptor(HandleObject obj, MutableHandle<JSPropertyDescriptor> desc) const;
     bool makeObject(JSContext *cx);
 
     /* Reset the descriptor entirely. */
@@ -281,6 +282,11 @@ class PropDescOperations
 
     JSPropertyOp getter() const { return desc()->getter(); }
     JSStrictPropertyOp setter() const { return desc()->setter(); }
+
+    void populatePropertyDescriptor(HandleObject obj,
+                                    MutableHandle<JSPropertyDescriptor> descriptor) const {
+        desc()->populatePropertyDescriptor(obj, descriptor);
+    }
 };
 
 template <typename Outer>