Eliminate some object casts

...mainly by giving a more precise type to global_proxy getters.

Change-Id: If4aef6b25baa2c641a45b177c59690e3ebfc3985
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1505578
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60072}

src/api.cc

@@ -6077,16 +6077,14 @@ MaybeLocal<Object> v8::Context::NewRemoteContext(
   Utils::ApiCheck(access_check_info->named_interceptor() != i::Object(),
                   "v8::Context::NewRemoteContext",
                   "Global template needs to have access check handlers.");
-  i::Handle<i::JSGlobalProxy> global_proxy =
-      CreateEnvironment<i::JSGlobalProxy>(
-          isolate, nullptr, global_template, global_object, 0,
-          DeserializeInternalFieldsCallback(), nullptr);
+  i::Handle<i::JSObject> global_proxy = CreateEnvironment<i::JSGlobalProxy>(
+      isolate, nullptr, global_template, global_object, 0,
+      DeserializeInternalFieldsCallback(), nullptr);
   if (global_proxy.is_null()) {
     if (isolate->has_pending_exception()) isolate->clear_pending_exception();
     return MaybeLocal<Object>();
   }
-  return Utils::ToLocal(
-      scope.CloseAndEscape(i::Handle<i::JSObject>::cast(global_proxy)));
+  return Utils::ToLocal(scope.CloseAndEscape(global_proxy));
 }
 
 void v8::Context::SetSecurityToken(Local<Value> token) {

src/bootstrapper.cc

@@ -349,8 +349,7 @@ void Bootstrapper::DetachGlobal(Handle<Context> env) {
       env->GetErrorsThrown());
 
   ReadOnlyRoots roots(isolate_);
-  Handle<JSGlobalProxy> global_proxy(JSGlobalProxy::cast(env->global_proxy()),
-                                     isolate_);
+  Handle<JSGlobalProxy> global_proxy(env->global_proxy(), isolate_);
   global_proxy->set_native_context(roots.null_value());
   JSObject::ForceSetPrototype(global_proxy, isolate_->factory()->null_value());
   global_proxy->map()->SetConstructor(roots.null_value());
@@ -5306,10 +5305,8 @@ bool Genesis::InstallExtension(Isolate* isolate,
 
 bool Genesis::ConfigureGlobalObjects(
     v8::Local<v8::ObjectTemplate> global_proxy_template) {
-  Handle<JSObject> global_proxy(
-      JSObject::cast(native_context()->global_proxy()), isolate());
-  Handle<JSObject> global_object(
-      JSObject::cast(native_context()->global_object()), isolate());
+  Handle<JSObject> global_proxy(native_context()->global_proxy(), isolate());
+  Handle<JSObject> global_object(native_context()->global_object(), isolate());
 
   if (!global_proxy_template.IsEmpty()) {
     // Configure the global proxy object.

src/compiler/js-native-context-specialization.cc

@@ -67,8 +67,7 @@ JSNativeContextSpecialization::JSNativeContextSpecialization(
       broker_(broker),
       flags_(flags),
       global_object_(native_context->global_object(), jsgraph->isolate()),
-      global_proxy_(JSGlobalProxy::cast(native_context->global_proxy()),
-                    jsgraph->isolate()),
+      global_proxy_(native_context->global_proxy(), jsgraph->isolate()),
       dependencies_(dependencies),
       zone_(zone),
       shared_zone_(shared_zone),

src/isolate-inl.h

@@ -94,11 +94,10 @@ Handle<JSGlobalObject> Isolate::global_object() {
   return handle(context()->global_object(), this);
 }
 
-Handle<JSObject> Isolate::global_proxy() {
+Handle<JSGlobalProxy> Isolate::global_proxy() {
   return handle(context()->global_proxy(), this);
 }
 
-
 Isolate::ExceptionScope::ExceptionScope(Isolate* isolate)
     : isolate_(isolate),
       pending_exception_(isolate_->pending_exception(), isolate_) {}

src/isolate.h

@@ -640,7 +640,7 @@ class Isolate final : private HiddenFactory {
   inline Handle<JSGlobalObject> global_object();
 
   // Returns the global proxy object of the current context.
-  inline Handle<JSObject> global_proxy();
+  inline Handle<JSGlobalProxy> global_proxy();
 
   static int ArchiveSpacePerThread() { return sizeof(ThreadLocalTop); }
   void FreeThreadResources() { thread_local_top()->Free(); }

src/objects/js-objects-inl.h

@@ -458,7 +458,7 @@ ACCESSORS(JSBoundFunction, bound_arguments, FixedArray, kBoundArgumentsOffset)
 ACCESSORS(JSFunction, raw_feedback_cell, FeedbackCell, kFeedbackCellOffset)
 
 ACCESSORS(JSGlobalObject, native_context, NativeContext, kNativeContextOffset)
-ACCESSORS(JSGlobalObject, global_proxy, JSObject, kGlobalProxyOffset)
+ACCESSORS(JSGlobalObject, global_proxy, JSGlobalProxy, kGlobalProxyOffset)
 
 ACCESSORS(JSGlobalProxy, native_context, Object, kNativeContextOffset)
 
@@ -954,7 +954,7 @@ Maybe<PropertyAttributes> JSReceiver::GetOwnElementAttributes(
 }
 
 bool JSGlobalObject::IsDetached() {
-  return JSGlobalProxy::cast(global_proxy())->IsDetachedFrom(*this);
+  return global_proxy()->IsDetachedFrom(*this);
 }
 
 bool JSGlobalProxy::IsDetachedFrom(JSGlobalObject global) const {

src/objects/js-objects.h

@@ -1159,7 +1159,7 @@ class JSGlobalObject : public JSObject {
   DECL_ACCESSORS(native_context, NativeContext)
 
   // [global proxy]: the global proxy object of the context
-  DECL_ACCESSORS(global_proxy, JSObject)
+  DECL_ACCESSORS(global_proxy, JSGlobalProxy)
 
   // Gets global object properties.
   inline GlobalDictionary global_dictionary();