Chromium does not throw the exception message by calling NPN_SetException from NPAPI plugin

content/common/npobject_proxy.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/npobject_proxy.h"
 
 #include "content/common/np_channel_base.h"
 #include "content/common/npobject_util.h"
 #include "content/common/plugin_messages.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
@@ skipping 44 matching lines @@
 }
 
 NPObjectProxy::NPObjectProxy(
     NPChannelBase* channel,
     int route_id,
     gfx::NativeViewId containing_window,
     const GURL& page_url)
     : channel_(channel),
       route_id_(route_id),
       containing_window_(containing_window),
-      page_url_(page_url) {
+      page_url_(page_url),
+      has_exception_thrown_(false) {
   channel_->AddRoute(route_id, this, this);
 }
 
 NPObjectProxy::~NPObjectProxy() {
   if (channel_.get()) {
     // This NPObjectProxy instance is now invalid and should not be reused for
     // requests initiated by plugins. We may receive requests for the
     // same NPObject in the context of the outgoing NPObjectMsg_Release call.
     // We should be creating new NPObjectProxy instances to wrap these
     // NPObjects.
@@ skipping 27 matching lines @@
   return reinterpret_cast<NPObject*>(new NPObjectWrapper);
 }
 
 void NPObjectProxy::NPDeallocate(NPObject* npObj) {
   NPObjectWrapper* obj = reinterpret_cast<NPObjectWrapper*>(npObj);
   delete obj->proxy;
   delete obj;
 }
 
 bool NPObjectProxy::OnMessageReceived(const IPC::Message& msg) {
-  NOTREACHED();
-  return false;
+  bool handled = true;
+
+  IPC_BEGIN_MESSAGE_MAP(NPObjectProxy, msg)
+    IPC_MESSAGE_HANDLER(NPObjectMsg_SetException, OnSetException)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
+  DCHECK(handled);
+  return true;
 }
 
 void NPObjectProxy::OnChannelError() {
   // Release our ref count of the plugin channel object, as it addrefs the
   // process.
   channel_ = NULL;
 }
 
+void NPObjectProxy::OnSetException(const std::string& msg) {
+  if (IsPluginProcess()) {
+    NOTREACHED() << "Should be only called from renderer process!";
+    return;
+  }
+
+  has_exception_thrown_ = true;
+
+  NPObject* obj = NULL;
+
+  if (channel()) {
+    obj = channel()->GetExistingNPObjectProxy(route_id_);
+  }
+
+  WebKit::WebBindings::setException(obj, msg.c_str());
+}
+
 bool NPObjectProxy::NPHasMethod(NPObject *obj,
                                 NPIdentifier name) {
   if (obj == NULL)
     return false;
 
   bool result = false;
   NPObjectProxy* proxy = GetProxy(obj);
 
   if (!proxy) {
     return obj->_class->hasMethod(obj, name);
   }
 
   NPIdentifier_Param name_param;
   CreateNPIdentifierParam(name, &name_param);
 
   proxy->Send(new NPObjectMsg_HasMethod(proxy->route_id(), name_param,
                                         &result));
+
   return result;
 }
 
 bool NPObjectProxy::NPInvoke(NPObject *obj,
                              NPIdentifier name,
                              const NPVariant *args,
                              uint32_t arg_count,
                              NPVariant *result) {
   return NPInvokePrivate(0, obj, false, name, args, arg_count, result);
 }
@@ skipping 58 matching lines @@
   // happens when everything runs in-process (while calling MessageBox window
   // messages are pumped).
   if (IsPluginProcess() && proxy->channel()) {
     msg->set_pump_messages_event(
         proxy->channel()->GetModalDialogEvent(containing_window));
   }
 
   GURL page_url = proxy->page_url_;
   proxy->Send(msg);
 
+  // In case of returning result is false and the NPObjectProxy instance
+  // has exception thrown, it means that NPN_SetException is called from
+  // NPAPI plugin during the process of invoking native method.
+  if (!result && proxy->HasExceptionThrown()) {
+    // Tell v8 engine that an exception has been already thrown via np_result
+    BOOLEAN_TO_NPVARIANT(true, *np_result);
+    proxy->SetExceptionThrown(false);
+  }
   // Send may delete proxy.
   proxy = NULL;
 
   if (!result)
     return false;
 
   CreateNPVariant(
       param_result, channel_copy, np_result, containing_window, page_url);
   return true;
 }
@@ skipping 200 matching lines @@
 
   // See comment in NPObjectProxy::NPInvokePrivate.
   if (IsPluginProcess() && proxy->channel()) {
     msg->set_pump_messages_event(
         proxy->channel()->GetModalDialogEvent(proxy->containing_window_));
   }
 
   GURL page_url = proxy->page_url_;
   proxy->Send(msg);
 
+  // An exception has been occurred during the process of handling
+  // NPObjectMsg_Construct on the peer side
+  if (!result && proxy->HasExceptionThrown()) {
+    BOOLEAN_TO_NPVARIANT(true, *np_result);
+    proxy->SetExceptionThrown(false);
+  }
+
   // Send may delete proxy.
   proxy = NULL;
 
   if (!result)
     return false;
 
   CreateNPVariant(
       param_result, channel_copy, np_result, containing_window, page_url);
   return true;
 }
@@ skipping 39 matching lines @@
   proxy->Send(msg);
   // Send may delete proxy.
   proxy = NULL;
   if (!result)
     return false;
 
   CreateNPVariant(
       result_param, channel.get(), result_var, containing_window, page_url);
   return true;
 }