Add 'error' parameter to 'window.onerror' handlers.

Source/core/dom/ScriptExecutionContext.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2012 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 10 matching lines @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 
 #include "config.h"
 #include "core/dom/ScriptExecutionContext.h"
 
+#include "bindings/v8/SerializedScriptValue.h"
 #include "core/dom/ContextLifecycleNotifier.h"
 #include "core/dom/ErrorEvent.h"
 #include "core/dom/EventTarget.h"
 #include "core/dom/MessagePort.h"
 #include "core/html/PublicURLManager.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/inspector/ScriptCallStack.h"
 #include "core/page/DOMTimer.h"
 #include "core/workers/WorkerGlobalScope.h"
 #include "core/workers/WorkerThread.h"
@@ skipping 146 matching lines @@
 }
 
 void ScriptExecutionContext::closeMessagePorts() {
     HashSet<MessagePort*>::iterator messagePortsEnd = m_messagePorts.end();
     for (HashSet<MessagePort*>::iterator iter = m_messagePorts.begin(); iter != messagePortsEnd; ++iter) {
         ASSERT((*iter)->scriptExecutionContext() == this);
         (*iter)->close();
     }
 }
 
-bool ScriptExecutionContext::sanitizeScriptError(String& errorMessage, int& lineNumber, int& columnNumber, String& sourceURL)
+bool ScriptExecutionContext::sanitizeScriptError(String& errorMessage, int& lineNumber, int& columnNumber, String& sourceURL, ScriptValue& error)
 {
     KURL targetURL = completeURL(sourceURL);
     if (securityOrigin()->canRequest(targetURL))
         return false;
     errorMessage = "Script error.";
     sourceURL = String();
     lineNumber = 0;
     columnNumber = 0;
+    error.clear();
     return true;
 }
 
-void ScriptExecutionContext::reportException(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, PassRefPtr<ScriptCallStack> callStack)
+void ScriptExecutionContext::reportException(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, PassRefPtr<ScriptCallStack> callStack, const ScriptValue& error)
 {
     if (m_inDispatchErrorEvent) {
         if (!m_pendingExceptions)
             m_pendingExceptions = adoptPtr(new Vector<OwnPtr<PendingException> >());
         m_pendingExceptions->append(adoptPtr(new PendingException(errorMessage, lineNumber, columnNumber, sourceURL, callStack)));
         return;
     }
 
     // First report the original exception and only then all the nested ones.
-    if (!dispatchErrorEvent(errorMessage, lineNumber, columnNumber, sourceURL))
+    if (!dispatchErrorEvent(errorMessage, lineNumber, columnNumber, sourceURL, error))
         logExceptionToConsole(errorMessage, sourceURL, lineNumber, columnNumber, callStack);
 
     if (!m_pendingExceptions)
         return;
 
     for (size_t i = 0; i < m_pendingExceptions->size(); i++) {
         PendingException* e = m_pendingExceptions->at(i).get();
         logExceptionToConsole(e->m_errorMessage, e->m_sourceURL, e->m_lineNumber, e->m_columnNumber, e->m_callStack);
     }
     m_pendingExceptions.clear();
 }
 
 void ScriptExecutionContext::addConsoleMessage(MessageSource source, MessageLevel level, const String& message, const String& sourceURL, unsigned lineNumber, ScriptState* state, unsigned long requestIdentifier)
 {
     addMessage(source, level, message, sourceURL, lineNumber, 0, state, requestIdentifier);
 }
 
-bool ScriptExecutionContext::dispatchErrorEvent(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL)
+bool ScriptExecutionContext::dispatchErrorEvent(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, const ScriptValue& errorObject)
 {
     EventTarget* target = errorEventTarget();
     if (!target)
         return false;
 
     String message = errorMessage;
     int line = lineNumber;
     int column = columnNumber;
     String sourceName = sourceURL;
-    sanitizeScriptError(message, line, column, sourceName);
+    ScriptValue error = errorObject;
+    sanitizeScriptError(message, line, column, sourceName, error);
 
     ASSERT(!m_inDispatchErrorEvent);
     m_inDispatchErrorEvent = true;
-    RefPtr<ErrorEvent> errorEvent = ErrorEvent::create(message, sourceName, line, column);
+    RefPtr<ErrorEvent> errorEvent = ErrorEvent::create(message, sourceName, line, column, error);

[adamk, 2013/07/30 15:46:41]

It seems like the thing holding you back from just storing the error on the
wrapper is a layering concern about calling toV8() here in
ScriptExecutionContext.cpp. But the amount of code would be tiny, something
like:

toV8(errorEvent)->SetHiddenValue(V8HiddenPropertyName::error(), error.v8Value())

I'm convinced sure hiding the V8 stuff behind ScriptValue is providing any value
here. The worldID workaround just seems weird.

[Mike West, 2013/07/30 15:53:37]

Yup. You're entirely correct. But there are only a handful of places in core
that use 'toV8', and it generally feels like a hack. This code shouldn't need to
know about worlds or wrappers. I'm not sure introducing those concepts is a good
idea.

[adamk, 2013/07/30 16:00:48]

No need to teach it about worlds (though note that DOMWrapperWorld is already
used in core), but hiding the existence of wrappers seems hardly worth it to me.
I guess this is just a difference of opinion about the aesthetics (as long as
your version doesn't leak memory, that is; where do you break the reference
cycle from script -> ErrorEvent -> script?).

     target->dispatchEvent(errorEvent);
     m_inDispatchErrorEvent = false;
     return errorEvent->defaultPrevented();
 }
 
 int ScriptExecutionContext::circularSequentialID()
 {
     ++m_circularSequentialID;
     if (m_circularSequentialID <= 0)
         m_circularSequentialID = 1;
@@ skipping 55 matching lines @@
 ScriptExecutionContext::Task::~Task()
 {
 }
 
 void ScriptExecutionContext::setDatabaseContext(DatabaseContext* databaseContext)
 {
     m_databaseContext = databaseContext;
 }
 
 } // namespace WebCore