Bug 1162296 - Use generic value traversal when scanning unboxed memory; r=jonco

--HG--
extra : rebase_source : 904492a7b966621a5fbc8905a0146891212f2f48

js/src/gc/Marking.cpp

@@ -782,6 +782,13 @@ js::GCMarker::traverse(S source, jsid id)
     DispatchIdTyped(TraverseFunctor<jsid, S>(), id, this, source);
 }
 
+template <typename S>
+void
+js::GCMarker::traverse(S source, Value v)
+{
+    DispatchValueTyped(TraverseFunctor<Value, S>(), v, this, source);
+}
+
 template <typename T>
 bool
 js::GCMarker::mark(T* thing)
@@ -1202,7 +1209,6 @@ GCMarker::processMarkStackTop(SliceBudget& budget)
         unboxedTraceList++;
         while (*unboxedTraceList != -1) {
             JSObject* obj2 = *reinterpret_cast<JSObject**>(unboxedMemory + *unboxedTraceList);
-            MOZ_ASSERT_IF(obj2, obj->compartment() == obj2->compartment());
             if (obj2)
                 traverse(obj, obj2);
             unboxedTraceList++;
@@ -1210,13 +1216,7 @@ GCMarker::processMarkStackTop(SliceBudget& budget)
         unboxedTraceList++;
         while (*unboxedTraceList != -1) {
             const Value& v = *reinterpret_cast<Value*>(unboxedMemory + *unboxedTraceList);
-            if (v.isString()) {
-                traverse(obj, v.toString());
-            } else if (v.isObject()) {
-                traverse(obj, &v.toObject());
-            } else if (v.isSymbol()) {
-                traverse(obj, v.toSymbol());
-            }
+            traverse(obj, v);
             unboxedTraceList++;
         }
         return;

js/src/gc/Marking.h

@@ -153,6 +153,7 @@ class GCMarker : public JSTracer
 
     // C++ requires explicit declarations of partial template instantiations.
     template <typename S> void traverse(S source, jsid target);
+    template <typename S> void traverse(S source, Value target);
 
     /*
      * Care must be taken changing the mark color from gray to black. The cycle

js/src/gc/Nursery-inl.h

@@ -22,7 +22,6 @@ js::Nursery::getForwardedPointer(JSObject** ref) const
     const gc::RelocationOverlay* overlay = reinterpret_cast<const gc::RelocationOverlay*>(*ref);
     if (!overlay->isForwarded())
         return false;
-    /* This static cast from Cell* restricts T to valid (GC thing) types. */
     *ref = static_cast<JSObject*>(overlay->forwardingAddress());
     return true;
 }