Treat weak references in context weakly in write barrier.

BUG=

Review URL: https://codereview.chromium.org/1152153004

Cr-Commit-Position: refs/heads/master@{#28658}

src/bootstrapper.cc

@@ -790,7 +790,8 @@ static void AddToWeakNativeContextList(Context* context) {
     }
   }
 #endif
-  context->set(Context::NEXT_CONTEXT_LINK, heap->native_contexts_list());
+  context->set(Context::NEXT_CONTEXT_LINK, heap->native_contexts_list(),
+               UPDATE_WEAK_WRITE_BARRIER);
   heap->set_native_contexts_list(context);
 }
 

src/contexts.cc

@@ -395,7 +395,7 @@ void Context::AddOptimizedFunction(JSFunction* function) {
   DCHECK(function->next_function_link()->IsUndefined());
 
   function->set_next_function_link(get(OPTIMIZED_FUNCTIONS_LIST));
-  set(OPTIMIZED_FUNCTIONS_LIST, function);
+  set(OPTIMIZED_FUNCTIONS_LIST, function, UPDATE_WEAK_WRITE_BARRIER);
 }
 
 
@@ -409,7 +409,8 @@ void Context::RemoveOptimizedFunction(JSFunction* function) {
            element_function->next_function_link()->IsJSFunction());
     if (element_function == function) {
       if (prev == NULL) {
-        set(OPTIMIZED_FUNCTIONS_LIST, element_function->next_function_link());
+        set(OPTIMIZED_FUNCTIONS_LIST, element_function->next_function_link(),
+            UPDATE_WEAK_WRITE_BARRIER);
       } else {
         prev->set_next_function_link(element_function->next_function_link());
       }
@@ -425,7 +426,7 @@ void Context::RemoveOptimizedFunction(JSFunction* function) {
 
 void Context::SetOptimizedFunctionsListHead(Object* head) {
   DCHECK(IsNativeContext());
-  set(OPTIMIZED_FUNCTIONS_LIST, head);
+  set(OPTIMIZED_FUNCTIONS_LIST, head, UPDATE_WEAK_WRITE_BARRIER);
 }
 
 
@@ -440,13 +441,13 @@ void Context::AddOptimizedCode(Code* code) {
   DCHECK(code->kind() == Code::OPTIMIZED_FUNCTION);
   DCHECK(code->next_code_link()->IsUndefined());
   code->set_next_code_link(get(OPTIMIZED_CODE_LIST));
-  set(OPTIMIZED_CODE_LIST, code);
+  set(OPTIMIZED_CODE_LIST, code, UPDATE_WEAK_WRITE_BARRIER);
 }
 
 
 void Context::SetOptimizedCodeListHead(Object* head) {
   DCHECK(IsNativeContext());
-  set(OPTIMIZED_CODE_LIST, head);
+  set(OPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER);
 }
 
 
@@ -458,7 +459,7 @@ Object* Context::OptimizedCodeListHead() {
 
 void Context::SetDeoptimizedCodeListHead(Object* head) {
   DCHECK(IsNativeContext());
-  set(DEOPTIMIZED_CODE_LIST, head);
+  set(DEOPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER);
 }
 
 

src/heap/objects-visiting.cc

@@ -287,7 +287,7 @@ struct WeakListVisitor<Code> {
 template <>
 struct WeakListVisitor<Context> {
   static void SetWeakNext(Context* context, Object* next) {
-    context->set(Context::NEXT_CONTEXT_LINK, next, UPDATE_WRITE_BARRIER);
+    context->set(Context::NEXT_CONTEXT_LINK, next, UPDATE_WEAK_WRITE_BARRIER);
   }
 
   static Object* WeakNext(Context* context) {

src/objects-inl.h

@@ -1275,13 +1275,15 @@ Maybe<bool> JSProxy::HasElementWithHandler(Handle<JSProxy> proxy,
     heap->RecordWrite(object->address(), offset);                       \
   }
 
-#define CONDITIONAL_WRITE_BARRIER(heap, object, offset, value, mode)    \
-  if (mode == UPDATE_WRITE_BARRIER) {                                   \
-    heap->incremental_marking()->RecordWrite(                           \
-      object, HeapObject::RawField(object, offset), value);             \
-    if (heap->InNewSpace(value)) {                                      \
-      heap->RecordWrite(object->address(), offset);                     \
-    }                                                                   \
+#define CONDITIONAL_WRITE_BARRIER(heap, object, offset, value, mode) \
+  if (mode != SKIP_WRITE_BARRIER) {                                  \
+    if (mode == UPDATE_WRITE_BARRIER) {                              \
+      heap->incremental_marking()->RecordWrite(                      \
+          object, HeapObject::RawField(object, offset), value);      \
+    }                                                                \
+    if (heap->InNewSpace(value)) {                                   \
+      heap->RecordWrite(object->address(), offset);                  \
+    }                                                                \
   }
 
 #ifndef V8_TARGET_ARCH_MIPS

src/objects.h

@@ -251,8 +251,15 @@ static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
 enum IcCheckType { ELEMENT, PROPERTY };
 
 
-// Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER.
-enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER };
+// SKIP_WRITE_BARRIER skips the write barrier.
+// UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and
+// only performs the generational part.
+// UPDATE_WRITE_BARRIER is doing the full barrier, marking and generational.
+enum WriteBarrierMode {
+  SKIP_WRITE_BARRIER,
+  UPDATE_WEAK_WRITE_BARRIER,
+  UPDATE_WRITE_BARRIER
+};
 
 
 // Indicates whether a value can be loaded as a constant.