void JavascriptExternalFunction::PrepareExternalCall(Js::Arguments * args)
{
ScriptContext * scriptContext = this->type->GetScriptContext();
Assert(!scriptContext->GetThreadContext()->IsDisableImplicitException());
scriptContext->VerifyAlive();
Assert(scriptContext->GetThreadContext()->IsScriptActive());
if (args->Info.Count == 0)
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_This_NullOrUndefined);
}
Var &thisVar = args->Values[0];
Js::TypeId typeId = Js::JavascriptOperators::GetTypeId(thisVar);
this->callCount++;
if (IS_JS_ETW(EventEnabledJSCRIPT_HOSTING_EXTERNAL_FUNCTION_CALL_START()))
{
JavascriptFunction* caller = nullptr;
// Lot the caller function if the call count of the external function pass certain threshold (randomly pick 256)
// we don't want to call stackwalk too often. The threshold can be adjusted as needed.
if (callCount >= ETW_MIN_COUNT_FOR_CALLER && ((callCount % ETW_MIN_COUNT_FOR_CALLER) == 0))
{
Js::JavascriptStackWalker stackWalker(scriptContext);
bool foundScriptCaller = false;
while(stackWalker.GetCaller(&caller))
{
if(caller != nullptr && Js::ScriptFunction::Is(caller))
{
foundScriptCaller = true;
break;
}
}
if(foundScriptCaller)
{
Var sourceString = caller->EnsureSourceString();
Assert(JavascriptString::Is(sourceString));
const char16* callerString = Js::JavascriptString::FromVar(sourceString)->GetSz();
char16* outString = (char16*)callerString;
int length = 0;
if (wcschr(callerString, _u('\n')) != NULL || wcschr(callerString, _u('\n')) != NULL)
{
length = Js::JavascriptString::FromVar(sourceString)->GetLength();
outString = HeapNewArray(char16, length+1);
int j = 0;
for (int i = 0; i < length; i++)
{
if (callerString[i] != _u('\n') && callerString[i] != L'\r')
{
outString[j++] = callerString[i];
}
}
outString[j] = L'\0';
}
JS_ETW(EventWriteJSCRIPT_HOSTING_CALLER_TO_EXTERNAL(scriptContext, this, typeId, outString, callCount));
if (outString != callerString)
{
HeapDeleteArray(length+1, outString);
}
#if DBG_DUMP
if (Js::Configuration::Global.flags.Trace.IsEnabled(Js::HostPhase))
{
Output::Print(_u("Large number of Call to trampoline: methodAddr= %p, Object typeid= %d, caller method= %s, callcount= %d\n"),
this, typeId, callerString, callCount);
}
#endif
}
}
JS_ETW(EventWriteJSCRIPT_HOSTING_EXTERNAL_FUNCTION_CALL_START(scriptContext, this, typeId));
#if DBG_DUMP
if (Js::Configuration::Global.flags.Trace.IsEnabled(Js::HostPhase))
{
Output::Print(_u("Call to trampoline: methodAddr= %p, Object typeid= %d\n"), this, typeId);
}
#endif
}
Js::RecyclableObject* directHostObject = nullptr;
switch(typeId)
{
case TypeIds_Integer:
#if FLOATVAR
case TypeIds_Number:
#endif // FLOATVAR
Assert(!Js::RecyclableObject::Is(thisVar));
break;
default:
{
Assert(Js::RecyclableObject::Is(thisVar));
ScriptContext* scriptContextThisVar = Js::RecyclableObject::FromVar(thisVar)->GetScriptContext();
// We need to verify "this" pointer is active as well. The problem is that DOM prototype functions are
// the same across multiple frames, and caller can do function.call(closedthis)
Assert(!scriptContext->GetThreadContext()->IsDisableImplicitException());
scriptContextThisVar->VerifyAlive();
// translate direct host for fastDOM.
switch(typeId)
{
case Js::TypeIds_GlobalObject:
{
Js::GlobalObject* srcGlobalObject = static_cast<Js::GlobalObject*>(thisVar);
directHostObject = srcGlobalObject->GetDirectHostObject();
// For jsrt, direct host object can be null. If thats the case don't change it.
if (directHostObject != nullptr)
{
thisVar = directHostObject;
}
}
break;
case Js::TypeIds_Undefined:
case Js::TypeIds_Null:
{
// Call to DOM function with this as "undefined" or "null"
// This should be converted to Global object
Js::GlobalObject* srcGlobalObject = scriptContextThisVar->GetGlobalObject() ;
directHostObject = srcGlobalObject->GetDirectHostObject();
// For jsrt, direct host object can be null. If thats the case don't change it.
if (directHostObject != nullptr)
{
thisVar = directHostObject;
}
}
break;
}
}
break;
}
}
void JavascriptExternalFunction::PrepareExternalCall(Js::Arguments * args)
{
ScriptContext * scriptContext = this->type->GetScriptContext();
Assert(!scriptContext->GetThreadContext()->IsDisableImplicitException());
scriptContext->VerifyAlive();
Assert(scriptContext->GetThreadContext()->IsScriptActive());
if (args->Info.Count == 0)
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_This_NullOrUndefined);
}
Var &thisVar = args->Values[0];
Js::TypeId typeId = Js::JavascriptOperators::GetTypeId(thisVar);
Js::RecyclableObject* directHostObject = nullptr;
switch(typeId)
{
case TypeIds_Integer:
#if FLOATVAR
case TypeIds_Number:
#endif // FLOATVAR
Assert(!Js::RecyclableObject::Is(thisVar));
break;
default:
{
Assert(Js::RecyclableObject::Is(thisVar));
ScriptContext* scriptContextThisVar = Js::RecyclableObject::FromVar(thisVar)->GetScriptContext();
// We need to verify "this" pointer is active as well. The problem is that DOM prototype functions are
// the same across multiple frames, and caller can do function.call(closedthis)
Assert(!scriptContext->GetThreadContext()->IsDisableImplicitException());
scriptContextThisVar->VerifyAlive();
// translate direct host for fastDOM.
switch(typeId)
{
case Js::TypeIds_GlobalObject:
{
Js::GlobalObject* srcGlobalObject = (Js::GlobalObject*)(void*)(thisVar);
directHostObject = srcGlobalObject->GetDirectHostObject();
// For jsrt, direct host object can be null. If thats the case don't change it.
if (directHostObject != nullptr)
{
thisVar = directHostObject;
}
}
break;
case Js::TypeIds_Undefined:
case Js::TypeIds_Null:
{
// Call to DOM function with this as "undefined" or "null"
// This should be converted to Global object
Js::GlobalObject* srcGlobalObject = scriptContextThisVar->GetGlobalObject() ;
directHostObject = srcGlobalObject->GetDirectHostObject();
// For jsrt, direct host object can be null. If thats the case don't change it.
if (directHostObject != nullptr)
{
thisVar = directHostObject;
}
}
break;
}
}
break;
}
}