[compiler] Make (Native)Context never-ever serialized

Bug: v8:7790
Change-Id: If558b6db7feed50bd0325a814bcab9e98ebd9493
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2991239
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75463}

src/compiler/heap-refs.h

@@ -464,91 +464,69 @@ class ContextRef : public HeapObjectRef {
 
   // {previous} decrements {depth} by 1 for each previous link successfully
   // followed. If {depth} != 0 on function return, then it only got partway to
-  // the desired depth. If {serialize} is true, then {previous} will cache its
-  // findings (unless concurrent inlining is enabled).
-  ContextRef previous(size_t* depth,
-                      SerializationPolicy policy =
-                          SerializationPolicy::kAssumeSerialized) const;
+  // the desired depth.
+  ContextRef previous(size_t* depth) const;
 
   // Only returns a value if the index is valid for this ContextRef.
-  base::Optional<ObjectRef> get(
-      int index, SerializationPolicy policy =
-                     SerializationPolicy::kAssumeSerialized) const;
+  base::Optional<ObjectRef> get(int index) const;
 
-  SourceTextModuleRef GetModule(SerializationPolicy policy) const;
+  SourceTextModuleRef GetModule() const;
 };
 
 // TODO(jgruber): Don't serialize NativeContext fields once all refs can be
 // created concurrently.
 
-#define BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(V) \
-  V(JSFunction, array_function)                    \
-  V(JSFunction, function_prototype_apply)          \
-  V(JSFunction, boolean_function)                  \
-  V(JSFunction, bigint_function)                   \
-  V(JSFunction, number_function)                   \
-  V(JSFunction, object_function)                   \
-  V(JSFunction, promise_function)                  \
-  V(JSFunction, promise_then)                      \
-  V(JSFunction, regexp_function)                   \
-  V(JSFunction, string_function)                   \
-  V(JSFunction, symbol_function)                   \
-  V(JSGlobalObject, global_object)                 \
-  V(JSGlobalProxy, global_proxy_object)            \
-  V(JSObject, promise_prototype)                   \
-  V(Map, bound_function_with_constructor_map)      \
-  V(Map, bound_function_without_constructor_map)   \
-  V(Map, js_array_holey_double_elements_map)       \
-  V(Map, js_array_holey_elements_map)              \
-  V(Map, js_array_holey_smi_elements_map)          \
-  V(Map, js_array_packed_double_elements_map)      \
-  V(Map, js_array_packed_elements_map)             \
-  V(Map, js_array_packed_smi_elements_map)         \
+#define BROKER_NATIVE_CONTEXT_FIELDS(V)          \
+  V(JSFunction, array_function)                  \
+  V(JSFunction, bigint_function)                 \
+  V(JSFunction, boolean_function)                \
+  V(JSFunction, function_prototype_apply)        \
+  V(JSFunction, number_function)                 \
+  V(JSFunction, object_function)                 \
+  V(JSFunction, promise_function)                \
+  V(JSFunction, promise_then)                    \
+  V(JSFunction, regexp_exec_function)            \
+  V(JSFunction, regexp_function)                 \
+  V(JSFunction, string_function)                 \
+  V(JSFunction, symbol_function)                 \
+  V(JSGlobalObject, global_object)               \
+  V(JSGlobalProxy, global_proxy_object)          \
+  V(JSObject, promise_prototype)                 \
+  V(Map, async_function_object_map)              \
+  V(Map, block_context_map)                      \
+  V(Map, bound_function_with_constructor_map)    \
+  V(Map, bound_function_without_constructor_map) \
+  V(Map, catch_context_map)                      \
+  V(Map, eval_context_map)                       \
+  V(Map, fast_aliased_arguments_map)             \
+  V(Map, function_context_map)                   \
+  V(Map, initial_array_iterator_map)             \
+  V(Map, initial_string_iterator_map)            \
+  V(Map, iterator_result_map)                    \
+  V(Map, js_array_holey_double_elements_map)     \
+  V(Map, js_array_holey_elements_map)            \
+  V(Map, js_array_holey_smi_elements_map)        \
+  V(Map, js_array_packed_double_elements_map)    \
+  V(Map, js_array_packed_elements_map)           \
+  V(Map, js_array_packed_smi_elements_map)       \
+  V(Map, map_key_iterator_map)                   \
+  V(Map, map_key_value_iterator_map)             \
+  V(Map, map_value_iterator_map)                 \
+  V(Map, set_key_value_iterator_map)             \
+  V(Map, set_value_iterator_map)                 \
+  V(Map, sloppy_arguments_map)                   \
+  V(Map, slow_object_with_null_prototype_map)    \
+  V(Map, strict_arguments_map)                   \
+  V(Map, with_context_map)                       \
   V(ScriptContextTable, script_context_table)
 
-#define BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(V) \
-  V(JSFunction, regexp_exec_function)
-
-#define BROKER_COMPULSORY_BACKGROUND_NATIVE_CONTEXT_FIELDS(V) \
-  V(Map, block_context_map)                                   \
-  V(Map, catch_context_map)                                   \
-  V(Map, eval_context_map)                                    \
-  V(Map, fast_aliased_arguments_map)                          \
-  V(Map, function_context_map)                                \
-  V(Map, initial_array_iterator_map)                          \
-  V(Map, initial_string_iterator_map)                         \
-  V(Map, iterator_result_map)                                 \
-  V(Map, sloppy_arguments_map)                                \
-  V(Map, slow_object_with_null_prototype_map)                 \
-  V(Map, strict_arguments_map)                                \
-  V(Map, with_context_map)
-
-// Those are set by Bootstrapper::ExportFromRuntime, which may not yet have
-// happened when Turbofan is invoked via --always-opt.
-#define BROKER_OPTIONAL_BACKGROUND_NATIVE_CONTEXT_FIELDS(V) \
-  V(Map, async_function_object_map)                         \
-  V(Map, map_key_iterator_map)                              \
-  V(Map, map_key_value_iterator_map)                        \
-  V(Map, map_value_iterator_map)                            \
-  V(Map, set_key_value_iterator_map)                        \
-  V(Map, set_value_iterator_map)
-
-#define BROKER_NATIVE_CONTEXT_FIELDS(V)                 \
-  BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(V)            \
-  BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(V)              \
-  BROKER_COMPULSORY_BACKGROUND_NATIVE_CONTEXT_FIELDS(V) \
-  BROKER_OPTIONAL_BACKGROUND_NATIVE_CONTEXT_FIELDS(V)
-
 class NativeContextRef : public ContextRef {
  public:
   DEFINE_REF_CONSTRUCTOR(NativeContext, ContextRef)
 
-  bool is_unserialized_heap_object() const;
-
   Handle<NativeContext> object() const;
 
   void Serialize();
-  void SerializeOnBackground();
 
 #define DECL_ACCESSOR(type, name) type##Ref name() const;
   BROKER_NATIVE_CONTEXT_FIELDS(DECL_ACCESSOR)

src/compiler/js-context-specialization.cc

@@ -257,9 +257,10 @@ Reduction JSContextSpecialization::ReduceJSGetImportMeta(Node* node) {
   if (!maybe_context.has_value()) return NoChange();
 
   ContextRef context = maybe_context.value();
-  SourceTextModuleRef module =
-      context.get(Context::EXTENSION_INDEX).value().AsSourceTextModule();
-  base::Optional<ObjectRef> import_meta = module.import_meta();
+  base::Optional<ObjectRef> module = context.get(Context::EXTENSION_INDEX);
+  if (!module.has_value()) return NoChange();
+  base::Optional<ObjectRef> import_meta =
+      module->AsSourceTextModule().import_meta();
   if (!import_meta.has_value()) return NoChange();
   if (!import_meta->IsJSObject()) {
     DCHECK(import_meta->IsTheHole());

src/compiler/js-heap-broker.cc

@@ -102,12 +102,6 @@ void JSHeapBroker::AttachLocalIsolate(OptimizedCompilationInfo* info,
   DCHECK_NOT_NULL(local_isolate_);
   local_isolate_->heap()->AttachPersistentHandles(
       info->DetachPersistentHandles());
-
-  if (is_concurrent_inlining()) {
-    // Ensure any serialization that happens on the background has been
-    // performed.
-    target_native_context().SerializeOnBackground();
-  }
 }
 
 void JSHeapBroker::DetachLocalIsolate(OptimizedCompilationInfo* info) {
@@ -140,8 +134,7 @@ void JSHeapBroker::SetTargetNativeContextRef(
     Handle<NativeContext> native_context) {
   DCHECK((mode() == kDisabled && !target_native_context_.has_value()) ||
          (mode() == kSerializing &&
-          target_native_context_->object().is_identical_to(native_context) &&
-          target_native_context_->is_unserialized_heap_object()));
+          target_native_context_->object().is_identical_to(native_context)));
   target_native_context_ = MakeRef(this, *native_context);
 }
 
@@ -700,8 +693,7 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForGlobalAccess(
     }
     ContextRef context_ref = MakeRef(this, context);
     if (immutable) {
-      context_ref.get(context_slot_index,
-                      SerializationPolicy::kSerializeIfNeeded);
+      context_ref.get(context_slot_index);
     }
     return *zone()->New<GlobalAccessFeedback>(context_ref, context_slot_index,
                                               immutable, nexus.kind());

src/compiler/serializer-for-background-compilation.cc

@@ -1498,13 +1498,11 @@ void SerializerForBackgroundCompilation::VisitInvokeIntrinsic(
     case Runtime::kInlineGetImportMetaObject: {
       Hints const& context_hints = environment()->current_context_hints();
       for (auto x : context_hints.constants()) {
-        MakeRef(broker(), Handle<Context>::cast(x))
-            .GetModule(SerializationPolicy::kSerializeIfNeeded)
-            .Serialize();
+        MakeRef(broker(), Handle<Context>::cast(x)).GetModule().Serialize();
       }
       for (auto x : context_hints.virtual_contexts()) {
         MakeRef(broker(), Handle<Context>::cast(x.context))
-            .GetModule(SerializationPolicy::kSerializeIfNeeded)
+            .GetModule()
             .Serialize();
       }
       break;
@@ -1546,8 +1544,7 @@ void SerializerForBackgroundCompilation::ProcessImmutableLoad(
     ContextRef const& context_ref, int slot, ContextProcessingMode mode,
     Hints* result_hints) {
   DCHECK_EQ(mode, kSerializeSlot);
-  base::Optional<ObjectRef> slot_value =
-      context_ref.get(slot, SerializationPolicy::kSerializeIfNeeded);
+  base::Optional<ObjectRef> slot_value = context_ref.get(slot);
 
   // If requested, record the object as a hint for the result value.
   if (result_hints != nullptr && slot_value.has_value()) {
@@ -1568,8 +1565,7 @@ void SerializerForBackgroundCompilation::ProcessContextAccess(
       // Walk this context to the given depth and serialize the slot found.
       ContextRef context_ref = MakeRef(broker(), Handle<Context>::cast(x));
       size_t remaining_depth = depth;
-      context_ref = context_ref.previous(
-          &remaining_depth, SerializationPolicy::kSerializeIfNeeded);
+      context_ref = context_ref.previous(&remaining_depth);
       if (remaining_depth == 0 && mode != kIgnoreSlot) {
         ProcessImmutableLoad(context_ref, slot, mode, result_hints);
       }
@@ -1580,8 +1576,7 @@ void SerializerForBackgroundCompilation::ProcessContextAccess(
       ContextRef context_ref =
           MakeRef(broker(), Handle<Context>::cast(x.context));
       size_t remaining_depth = depth - x.distance;
-      context_ref = context_ref.previous(
-          &remaining_depth, SerializationPolicy::kSerializeIfNeeded);
+      context_ref = context_ref.previous(&remaining_depth);
       if (remaining_depth == 0 && mode != kIgnoreSlot) {
         ProcessImmutableLoad(context_ref, slot, mode, result_hints);
       }
@@ -1994,10 +1989,7 @@ void SerializerForBackgroundCompilation::VisitCallJSRuntime(
     BytecodeArrayIterator* iterator) {
   const int runtime_index = iterator->GetNativeContextIndexOperand(0);
   ObjectRef constant =
-      broker()
-          ->target_native_context()
-          .get(runtime_index, SerializationPolicy::kSerializeIfNeeded)
-          .value();
+      broker()->target_native_context().get(runtime_index).value();
   Hints const callee = Hints::SingleConstant(constant.object(), zone());
   interpreter::Register first_reg = iterator->GetRegisterOperand(1);
   int reg_count = static_cast<int>(iterator->GetRegisterCountOperand(2));

src/objects/contexts.h

@@ -694,7 +694,7 @@ class NativeContext : public Context {
   // initialization.  This function should *not* be used from anywhere other
   // than heap-refs.cc.
   // TODO(jgruber): Remove this function after NativeContextRef is actually
-  // never serialized and BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS is removed.
+  // never serialized and BROKER_NATIVE_CONTEXT_FIELDS is removed.
   JSGlobalObject global_object() { return Context::global_object(); }
   JSGlobalObject global_object(AcquireLoadTag) {
     return Context::global_object();