Backed out changeset e554fdb83c5f (bug 1163810) on a CLOSED TREE

js/src/gc/Marking.cpp

@@ -1266,7 +1266,7 @@ GCMarker::processMarkStackTop(SliceBudget& budget)
             JSObject* obj2 = &v.toObject();
             MOZ_ASSERT(obj->compartment() == obj2->compartment());
             if (mark(obj2)) {
-                // Save the rest of this value array for later and start scanning obj2's children.
+                // Save the rest of this value array for later and start scanning obj2's children.N
                 pushValueArray(obj, vp, end);
                 obj = obj2;
                 goto scan_obj;

js/src/jsgc.cpp

@@ -7162,19 +7162,40 @@ JS::IsIncrementalBarrierNeeded(JSContext* cx)
     return IsIncrementalBarrierNeeded(cx->runtime());
 }
 
-struct IncrementalReferenceBarrierFunctor {
-    template <typename T> void operator()(gc::Cell* cell) {
-        T::writeBarrierPre(static_cast<T*>(cell));
-    }
-};
-
 JS_PUBLIC_API(void)
 JS::IncrementalReferenceBarrier(GCCellPtr thing)
 {
     if (!thing)
         return;
 
-    CallTyped(IncrementalReferenceBarrierFunctor(), thing.kind(), thing.asCell());
+    if (thing.isString() && thing.toString()->isPermanentAtom())
+        return;
+
+#ifdef DEBUG
+    Zone* zone = thing.isObject()
+                 ? thing.toObject()->zone()
+                 : thing.asCell()->asTenured().zone();
+    MOZ_ASSERT(!zone->runtimeFromMainThread()->isHeapMajorCollecting());
+#endif
+
+    switch(thing.kind()) {
+      case JSTRACE_OBJECT: return JSObject::writeBarrierPre(thing.toObject());
+      case JSTRACE_STRING: return JSString::writeBarrierPre(thing.toString());
+      case JSTRACE_SCRIPT: return JSScript::writeBarrierPre(thing.toScript());
+      case JSTRACE_SYMBOL: return JS::Symbol::writeBarrierPre(thing.toSymbol());
+      case JSTRACE_LAZY_SCRIPT:
+        return LazyScript::writeBarrierPre(static_cast<LazyScript*>(thing.asCell()));
+      case JSTRACE_JITCODE:
+        return jit::JitCode::writeBarrierPre(static_cast<jit::JitCode*>(thing.asCell()));
+      case JSTRACE_SHAPE:
+        return Shape::writeBarrierPre(static_cast<Shape*>(thing.asCell()));
+      case JSTRACE_BASE_SHAPE:
+        return BaseShape::writeBarrierPre(static_cast<BaseShape*>(thing.asCell()));
+      case JSTRACE_OBJECT_GROUP:
+        return ObjectGroup::writeBarrierPre(static_cast<ObjectGroup*>(thing.asCell()));
+      default:
+        MOZ_CRASH("Invalid trace kind in IncrementalReferenceBarrier.");
+    }
 }
 
 JS_PUBLIC_API(void)

js/src/vm/Symbol.h

@@ -62,11 +62,6 @@ class Symbol : public js::gc::TenuredCell
     }
     inline void finalize(js::FreeOp*) {}
 
-    static MOZ_ALWAYS_INLINE void writeBarrierPre(Symbol* thing) {
-        if (thing && !thing->isWellKnownSymbol())
-            thing->asTenured().writeBarrierPre(thing);
-    }
-
 #ifdef DEBUG
     void dump(FILE* fp = stderr);
 #endif