[compiler] Replace ScopeInfoData with direct reads

As part of this, introduce a new ObjectData kind for objects that we
want to read directly from the background thread rather than serialize.
ScopeInfoRef is the first user of that.

For details, see:
https://docs.google.com/document/d/1U6x6Q2bpylfxS55nxSe17yyBW0bQG-ycoBhVA82VmS0/edit?usp=sharing

Bug: v8:7790
Change-Id: Ia3cda4f67d3922367afa4a5da2aeaae7160cf1f2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2346405
Auto-Submit: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69473}

src/ast/scopes.h

@@ -705,8 +705,6 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
 
   void SetDefaults();
 
-  void set_scope_info(Handle<ScopeInfo> scope_info);
-
   friend class DeclarationScope;
   friend class ClassScope;
   friend class ScopeTestHelper;

src/codegen/compiler.cc

@@ -596,7 +596,7 @@ void UpdateSharedFunctionFlagsAfterCompilation(FunctionLiteral* literal,
   shared_info.set_has_static_private_methods_or_accessors(
       literal->has_static_private_methods_or_accessors());
 
-  shared_info.set_scope_info(*literal->scope()->scope_info());
+  shared_info.SetScopeInfo(*literal->scope()->scope_info());
 }
 
 // Finalize a single compilation job. This function can return

src/compiler/bytecode-graph-builder.cc

@@ -1785,7 +1785,7 @@ BytecodeGraphBuilder::Environment* BytecodeGraphBuilder::CheckContextExtensions(
   // in the same scope as the variable itself has no way of shadowing it.
   Environment* slow_environment = nullptr;
   for (uint32_t d = 0; d < depth; d++) {
-    if (scope_info.HasContextExtension()) {
+    if (scope_info.HasContextExtensionSlot()) {
       slow_environment = CheckContextExtensionAtDepth(slow_environment, d);
     }
     DCHECK_IMPLIES(!scope_info.HasOuterScopeInfo(), d + 1 == depth);

src/compiler/heap-refs.h

@@ -49,57 +49,58 @@ enum class OddballType : uint8_t {
 
 // This list is sorted such that subtypes appear before their supertypes.
 // DO NOT VIOLATE THIS PROPERTY!
-#define HEAP_BROKER_OBJECT_LIST(V) \
-  /* Subtypes of JSObject */       \
-  V(JSArray)                       \
-  V(JSBoundFunction)               \
-  V(JSDataView)                    \
-  V(JSFunction)                    \
-  V(JSGlobalObject)                \
-  V(JSGlobalProxy)                 \
-  V(JSRegExp)                      \
-  V(JSTypedArray)                  \
-  /* Subtypes of Context */        \
-  V(NativeContext)                 \
-  /* Subtypes of FixedArray */     \
-  V(Context)                       \
-  V(ObjectBoilerplateDescription)  \
-  V(ScopeInfo)                     \
-  V(ScriptContextTable)            \
-  /* Subtypes of FixedArrayBase */ \
-  V(BytecodeArray)                 \
-  V(FixedArray)                    \
-  V(FixedDoubleArray)              \
-  /* Subtypes of Name */           \
-  V(InternalizedString)            \
-  V(String)                        \
-  V(Symbol)                        \
-  /* Subtypes of JSReceiver */     \
-  V(JSObject)                      \
-  /* Subtypes of HeapObject */     \
-  V(AccessorInfo)                  \
-  V(AllocationSite)                \
-  V(ArrayBoilerplateDescription)   \
-  V(BigInt)                        \
-  V(CallHandlerInfo)               \
-  V(Cell)                          \
-  V(Code)                          \
-  V(DescriptorArray)               \
-  V(FeedbackCell)                  \
-  V(FeedbackVector)                \
-  V(FixedArrayBase)                \
-  V(FunctionTemplateInfo)          \
-  V(HeapNumber)                    \
-  V(JSReceiver)                    \
-  V(Map)                           \
-  V(Name)                          \
-  V(PropertyCell)                  \
-  V(SharedFunctionInfo)            \
-  V(SourceTextModule)              \
-  V(TemplateObjectDescription)     \
-  /* Subtypes of Object */         \
+#define HEAP_BROKER_SERIALIZED_OBJECT_LIST(V) \
+  /* Subtypes of JSObject */                  \
+  V(JSArray)                                  \
+  V(JSBoundFunction)                          \
+  V(JSDataView)                               \
+  V(JSFunction)                               \
+  V(JSGlobalObject)                           \
+  V(JSGlobalProxy)                            \
+  V(JSRegExp)                                 \
+  V(JSTypedArray)                             \
+  /* Subtypes of Context */                   \
+  V(NativeContext)                            \
+  /* Subtypes of FixedArray */                \
+  V(Context)                                  \
+  V(ObjectBoilerplateDescription)             \
+  V(ScriptContextTable)                       \
+  /* Subtypes of FixedArrayBase */            \
+  V(BytecodeArray)                            \
+  V(FixedArray)                               \
+  V(FixedDoubleArray)                         \
+  /* Subtypes of Name */                      \
+  V(InternalizedString)                       \
+  V(String)                                   \
+  V(Symbol)                                   \
+  /* Subtypes of JSReceiver */                \
+  V(JSObject)                                 \
+  /* Subtypes of HeapObject */                \
+  V(AccessorInfo)                             \
+  V(AllocationSite)                           \
+  V(ArrayBoilerplateDescription)              \
+  V(BigInt)                                   \
+  V(CallHandlerInfo)                          \
+  V(Cell)                                     \
+  V(Code)                                     \
+  V(DescriptorArray)                          \
+  V(FeedbackCell)                             \
+  V(FeedbackVector)                           \
+  V(FixedArrayBase)                           \
+  V(FunctionTemplateInfo)                     \
+  V(HeapNumber)                               \
+  V(JSReceiver)                               \
+  V(Map)                                      \
+  V(Name)                                     \
+  V(PropertyCell)                             \
+  V(SharedFunctionInfo)                       \
+  V(SourceTextModule)                         \
+  V(TemplateObjectDescription)                \
+  /* Subtypes of Object */                    \
   V(HeapObject)
 
+#define HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(V) V(ScopeInfo)
+
 class CompilationDependencies;
 struct FeedbackSource;
 class JSHeapBroker;
@@ -107,7 +108,8 @@ class ObjectData;
 class PerIsolateCompilerCache;
 class PropertyAccessInfo;
 #define FORWARD_DECL(Name) class Name##Ref;
-HEAP_BROKER_OBJECT_LIST(FORWARD_DECL)
+HEAP_BROKER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
+HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
 #undef FORWARD_DECL
 
 class V8_EXPORT_PRIVATE ObjectRef {
@@ -127,11 +129,13 @@ class V8_EXPORT_PRIVATE ObjectRef {
   int AsSmi() const;
 
 #define HEAP_IS_METHOD_DECL(Name) bool Is##Name() const;
-  HEAP_BROKER_OBJECT_LIST(HEAP_IS_METHOD_DECL)
+  HEAP_BROKER_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
+  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
 #undef HEAP_IS_METHOD_DECL
 
 #define HEAP_AS_METHOD_DECL(Name) Name##Ref As##Name() const;
-  HEAP_BROKER_OBJECT_LIST(HEAP_AS_METHOD_DECL)
+  HEAP_BROKER_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
+  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
 #undef HEAP_AS_METHOD_DECL
 
   bool IsNullOrUndefined() const;
@@ -760,8 +764,7 @@ class ScopeInfoRef : public HeapObjectRef {
 
   int ContextLength() const;
   bool HasOuterScopeInfo() const;
-  int Flags() const;
-  bool HasContextExtension() const;
+  bool HasContextExtensionSlot() const;
 
   // Only serialized via SerializeScopeInfoChain.
   ScopeInfoRef OuterScopeInfo() const;

src/compiler/pipeline.cc

@@ -1508,6 +1508,9 @@ struct TyperPhase {
     roots.push_back(data->jsgraph()->TrueConstant());
     roots.push_back(data->jsgraph()->FalseConstant());
 
+    // The typer inspects heap objects, so we need to unpark the local heap.
+    UnparkedScopeIfNeeded scope(data->broker());
+
     LoopVariableOptimizer induction_vars(data->jsgraph()->graph(),
                                          data->common(), temp_zone);
     if (FLAG_turbo_loop_variable) induction_vars.Run();

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

@@ -1775,12 +1775,6 @@ void SerializerForBackgroundCompilation::VisitForInPrepare(
 
 void SerializerForBackgroundCompilation::ProcessCreateContext(
     interpreter::BytecodeArrayIterator* iterator, int scopeinfo_operand_index) {
-  Handle<ScopeInfo> scope_info =
-      Handle<ScopeInfo>::cast(iterator->GetConstantForIndexOperand(
-          scopeinfo_operand_index, broker()->isolate()));
-  ScopeInfoRef scope_info_ref(broker(), scope_info);
-  scope_info_ref.SerializeScopeInfoChain();
-
   Hints const& current_context_hints = environment()->current_context_hints();
   Hints result_hints;
 

src/objects/object-macros.h

@@ -79,6 +79,11 @@
 #define DECL_SYNCHRONIZED_INT_ACCESSORS(name) \
   DECL_SYNCHRONIZED_PRIMITIVE_ACCESSORS(name, int)
 
+#define DECL_SYNCHRONIZED_ACCESSORS(name, type) \
+  DECL_GETTER(synchronized_##name, type)        \
+  inline void set_synchronized_##name(          \
+      type value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
 #define DECL_INT32_ACCESSORS(name) DECL_PRIMITIVE_ACCESSORS(name, int32_t)
 
 #define DECL_UINT16_ACCESSORS(name) \

src/objects/shared-function-info-inl.h

@@ -101,6 +101,8 @@ SYNCHRONIZED_ACCESSORS(SharedFunctionInfo, function_data, Object,
                        kFunctionDataOffset)
 ACCESSORS(SharedFunctionInfo, name_or_scope_info, Object,
           kNameOrScopeInfoOffset)
+SYNCHRONIZED_ACCESSORS(SharedFunctionInfo, synchronized_name_or_scope_info,
+                       Object, kNameOrScopeInfoOffset)
 ACCESSORS(SharedFunctionInfo, script_or_debug_info, HeapObject,
           kScriptOrDebugInfoOffset)
 
@@ -338,8 +340,16 @@ ScopeInfo SharedFunctionInfo::scope_info() const {
   return GetReadOnlyRoots().empty_scope_info();
 }
 
-void SharedFunctionInfo::set_scope_info(ScopeInfo scope_info,
-                                        WriteBarrierMode mode) {
+ScopeInfo SharedFunctionInfo::synchronized_scope_info() const {
+  Object maybe_scope_info = synchronized_name_or_scope_info();
+  if (maybe_scope_info.IsScopeInfo()) {
+    return ScopeInfo::cast(maybe_scope_info);
+  }
+  return GetReadOnlyRoots().empty_scope_info();
+}
+
+void SharedFunctionInfo::SetScopeInfo(ScopeInfo scope_info,
+                                      WriteBarrierMode mode) {
   // Move the existing name onto the ScopeInfo.
   Object name = name_or_scope_info();
   if (name.IsScopeInfo()) {
@@ -351,7 +361,7 @@ void SharedFunctionInfo::set_scope_info(ScopeInfo scope_info,
   if (HasInferredName() && inferred_name().length() != 0) {
     scope_info.SetInferredFunctionName(inferred_name());
   }
-  set_raw_scope_info(scope_info, mode);
+  set_synchronized_name_or_scope_info(scope_info, mode);
 }
 
 void SharedFunctionInfo::set_raw_scope_info(ScopeInfo scope_info,

src/objects/shared-function-info.h

@@ -216,12 +216,16 @@ class SharedFunctionInfo : public HeapObject {
   static const int kNotFound = -1;
 
   // [scope_info]: Scope info.
-  DECL_ACCESSORS(scope_info, ScopeInfo)
+  DECL_GETTER(scope_info, ScopeInfo)
+  DECL_GETTER(synchronized_scope_info, ScopeInfo)
 
   // Set scope_info without moving the existing name onto the ScopeInfo.
   inline void set_raw_scope_info(ScopeInfo scope_info,
                                  WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
+  inline void SetScopeInfo(ScopeInfo scope_info,
+                           WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
   inline bool is_script() const;
   inline bool needs_script_context() const;
 
@@ -662,6 +666,7 @@ class SharedFunctionInfo : public HeapObject {
   // [name_or_scope_info]: Function name string, kNoSharedNameSentinel or
   // ScopeInfo.
   DECL_ACCESSORS(name_or_scope_info, Object)
+  DECL_SYNCHRONIZED_ACCESSORS(name_or_scope_info, Object)
 
   // [outer scope info] The outer scope info, needed to lazily parse this
   // function.