Convert function.caller to API-style accessor.

src/accessors.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 33 matching lines @@
 
 
 static Handle<AccessorInfo> MakeAccessor(Isolate* isolate,
                                          Handle<String> name,
                                          AccessorGetterCallback getter,
                                          AccessorSetterCallback setter,
                                          PropertyAttributes attributes) {
   Factory* factory = isolate->factory();
   Handle<ExecutableAccessorInfo> info = factory->NewExecutableAccessorInfo();
   info->set_property_attributes(attributes);
-  info->set_all_can_read(true);
-  info->set_all_can_write(true);
+  info->set_all_can_read(false);
+  info->set_all_can_write(false);
   info->set_prohibits_overwriting(false);
   info->set_name(*name);
   Handle<Object> get = v8::FromCData(isolate, getter);
   Handle<Object> set = v8::FromCData(isolate, setter);
   info->set_getter(*get);
   info->set_setter(*set);
   return info;
 }
 
 
@@ skipping 1117 matching lines @@
     ASSERT(functions_.length() > 0);
     frame_iterator_.Advance();
     index_ = functions_.length() - 1;
   }
   JavaScriptFrameIterator frame_iterator_;
   List<JSFunction*> functions_;
   int index_;
 };
 
 
-Object* Accessors::FunctionGetCaller(Isolate* isolate,
-                                     Object* object,
-                                     void*) {
-  HandleScope scope(isolate);
+MaybeHandle<JSFunction> FindCaller(Isolate* isolate,
+                                   Handle<JSFunction> function) {
   DisallowHeapAllocation no_allocation;
-  JSFunction* holder = FindInstanceOf<JSFunction>(isolate, object);
-  if (holder == NULL) return isolate->heap()->undefined_value();
-  if (holder->shared()->native()) return isolate->heap()->null_value();
-  Handle<JSFunction> function(holder, isolate);
-
   FrameFunctionIterator it(isolate, no_allocation);
-
+  if (function->shared()->native()) {
+    return MaybeHandle<JSFunction>();
+  }
   // Find the function from the frames.
   if (!it.Find(*function)) {
     // No frame corresponding to the given function found. Return null.
-    return isolate->heap()->null_value();
+    return MaybeHandle<JSFunction>();
   }
-
   // Find previously called non-toplevel function.
   JSFunction* caller;
   do {
     caller = it.next();
-    if (caller == NULL) return isolate->heap()->null_value();
+    if (caller == NULL) return MaybeHandle<JSFunction>();
   } while (caller->shared()->is_toplevel());
 
   // If caller is a built-in function and caller's caller is also built-in,
   // use that instead.
   JSFunction* potential_caller = caller;
   while (potential_caller != NULL && potential_caller->IsBuiltin()) {
     caller = potential_caller;
     potential_caller = it.next();
   }
   if (!caller->shared()->native() && potential_caller != NULL) {
     caller = potential_caller;
   }
   // If caller is bound, return null. This is compatible with JSC, and
   // allows us to make bound functions use the strict function map
   // and its associated throwing caller and arguments.
   if (caller->shared()->bound()) {
-    return isolate->heap()->null_value();
+    return MaybeHandle<JSFunction>();
   }
   // Censor if the caller is not a sloppy mode function.
   // Change from ES5, which used to throw, see:
   // https://bugs.ecmascript.org/show_bug.cgi?id=310
   if (caller->shared()->strict_mode() == STRICT) {
-    return isolate->heap()->null_value();
+    return MaybeHandle<JSFunction>();
   }
-
-  return caller;
+  return Handle<JSFunction>(caller);
 }
 
 
-const AccessorDescriptor Accessors::FunctionCaller = {
-  FunctionGetCaller,
-  ReadOnlySetAccessor,
-  0
-};
+void Accessors::FunctionCallerGetter(
+    v8::Local<v8::String> name,
+    const v8::PropertyCallbackInfo<v8::Value>& info) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
+  HandleScope scope(isolate);
+  Handle<Object> object = Utils::OpenHandle(*info.This());
+  MaybeHandle<JSFunction> maybe_function;
+  {
+    DisallowHeapAllocation no_allocation;
+    JSFunction* function = FindInstanceOf<JSFunction>(isolate, *object);
+    if (function != NULL) maybe_function = Handle<JSFunction>(function);
+  }
+  Handle<JSFunction> function;
+  Handle<Object> result;
+  if (maybe_function.ToHandle(&function)) {
+    MaybeHandle<JSFunction> maybe_caller;
+    maybe_caller = FindCaller(isolate, function);
+    Handle<JSFunction> caller;
+    if (maybe_caller.ToHandle(&caller)) {
+      result = caller;
+    } else {
+      result = isolate->factory()->null_value();
+    }
+  } else {
+    result = isolate->factory()->undefined_value();
+  }
+  info.GetReturnValue().Set(Utils::ToLocal(result));
+}
+
+
+void Accessors::FunctionCallerSetter(
+    v8::Local<v8::String> name,
+    v8::Local<v8::Value> val,
+    const v8::PropertyCallbackInfo<void>& info) {
+  // Do nothing.
+}
+
+
+Handle<AccessorInfo> Accessors::FunctionCallerInfo(
+      Isolate* isolate, PropertyAttributes attributes) {
+  return MakeAccessor(isolate,
+                      isolate->factory()->caller_string(),
+                      &FunctionCallerGetter,
+                      &FunctionCallerSetter,
+                      attributes);
+}
 
 
 //
 // Accessors::MakeModuleExport
 //
 
 static void ModuleGetExport(
     v8::Local<v8::String> property,
     const v8::PropertyCallbackInfo<v8::Value>& info) {
   JSModule* instance = JSModule::cast(*v8::Utils::OpenHandle(*info.Holder()));
@@ skipping 48 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal