i use the newer version of the v8 library. When i run demo from this page(process.cc),
my program crash when GetInternalField is called in UnwrapMap function. Does anyone have a similar problem, or does they know how to solve it?
Here example:
map<string, string>* JsHttpRequestProcessor::UnwrapMap(Local<Object> obj) {
Local<External> field = Local<External>::Cast(obj->GetInternalField(0)); // here segmentation fault
void* ptr = field->Value();
return static_cast<map<string, string>*>(ptr);
}
EDIT:
I solved my problem. I had to insert macro V8_COMPRESS_POINTERS = 1. Thank you
The provided sample works fine here; did you modify it in any way? How exactly are you running it?
You can only call obj->GetInternalField(0) if you know that obj is an object with internal fields. You can use obj->InternalFieldCount() to check. Objects only have internal fields if you, the embedder, gave them any. If you are trying to convert a regular JavaScript object to a C++ map, you'll have to iterate over its properties, not its internal fields.
Related
I implemented Aspose.Cells and Aspose.PDF into our companies existing application.
While I had some trouble with this (mostly caused by the fact that I tried to implement both APIs into the exat same file which was a bad idea)
I figured out how to make it work more or less.
My Problem now is while Aspose.Cells works perfectly fine and doesn't seem to have any unusual behavior Aspose.PDF already struggles with setting the license and even when I eventually got this to work I can't even initiate a Aspose::Pdf::Document.
So the first totally unusual thing is the way I had to set the License in the Example code given with the Aspose Package and in the official resources the license is set like this.
auto lic = System::MakeObject<Aspose::Pdf::License>();
lic->SetlLicense("c:\\Foo\fooproj\\Aspose.Total.C++.lic");
This code won't run on my machine and cause the error.
Rough Translation
food.exe triggered a breakpoint
Original
food.exe Hat einen Haltepunkt ausgelöst
The same happens when I initialise a System::String with a emtpy constructor like this.
auto lic = System::MakeObject<Aspose::Pdf::License>();
System::String str;
str.FromUtf8("C:\\foo\fooproj\\Aspose.Total.C++.lic");
lic->SetLicense(str);
BUT if I initialise the System::String with an empty String in the first place setting the license seems to work just fine so this works.
auto lic = System::MakeObject<Aspose::Pdf::License>();
System::String str(u"");
str.FromUtf8("C:\\Projekte\\Aspose\\Lizens\\Aspose.Total.C++.lic");
lic->SetLicense(str);
If this code above works and I try to make an object from Aspose::Pdf::Document this will crash.
void Aspose_pdf::helloWorld()
{
auto doc = System::MakeObject<Aspose::Pdf::Document>();
.....
.....
}
I actually have no idea what's going on. I am not using any using namespace commands at the moment.
Would be greate if someone had an idea how to fix this.
Edit:
The error occures exactly in smart_ptr.h in the following function.
typename std::enable_if<!IsSmartPtr<T>::value, SmartPtr<T> >::type MakeObject(Args&&... args)
{
System::Detail::OwnNextObject ownershipSentry;
T *const object = ::new T(std::forward<Args>(args)...);
ownershipSentry.CreatedSuccessfully(object);
return SmartPtr<T>(object);
}
in the second line so T *const object = ::new T(std::forward<Args>(args)...);
is "causing" the error or atleast here the error will ne triggered.
Edit2:
Here you will find a simple example of how my code looks in general.
I Started with implementing Aspose.Pdf into my Programm so I edited my
Additional Library directories,additional dependencies, additional include directories,preprozessor definitions and my stacksize to fit these settings given in the Aspose.Pdf examples.
After this I created my Aspose_Pdf class and tested it. worked perferctly so far.
After this I made the same edits to fit Aspose.Cells aswell. Also I created a class Aspose_Cells and tested it. While this worked now my Aspose_Pdf class stoped working. After a little time passed I managed to atleast get the License Activation for Aspose_Pdf to work from this point on I had the problems described above.
Additional Dependencies:
...
Aspose.PDF_vc141x64d.lib
aspose_cpp_vc141x64d.lib
Aspose.Cells.lib
Additional Librariedirectories:
...
..\Aspose\Aspose.PDF\lib\Debug
..\Aspose\Aspose.Cells\lib64
additional Includedirectories
...
..\Aspose\Aspose.PDF\lib\Debug
..\Aspose\Aspose.PDF\include\asposecpplib
..\Aspose\Aspose.PDF\include\Aspose.Pdf.Cpp
..\Aspose\Aspose.Cells\Include
..\Aspose\Aspose.Cells\Include\icu\include
..\Aspose\Aspose.Cells\Include\boost
I've never heard about Aspose.Pdf neither I know how does System::MakeObject< work. But for me it looks that all the code might be simplified to next:
Aspose::Pdf::License^ lic = gcnew Aspose::Pdf::License();
System::String^ str = "C:\\foo\\fooproj\\Aspose.Total.C++.lic";
lic->SetLicense(str);
When it comes to Pdf.Document the initialization might look like this:
Aspose::Pdf::Document^ doc = gcnew Aspose::Pdf::Document();
Currently, I'm working on compiling old .cpp classes under C++ Builder XE. Apart from many troubles, there is one which I have completely no idea how to solve.
My code:
String txt = "<Not so long sql query>";
int licz = some_function(txt, dzeFDS); //1
//assigning licz to somewhere
txt = "<much longer query>";
licz = some_function(txt, budFDS); //2
Problem is that during second call of some_function program is stopped and i have this alert:
First chance exception at $75A1C42D. Exception class EDatabaseError with message 'budFDS: Type mismatch for field 'Function', expecting: String actual: WideString'. Process Call.exe (1896)
It's strange form be, bacause first call of some_function works fine, but this second one (with arguments with the same type) doesn't.
some_function code:
int __fastcall some_function(String txt, TIBDataSet *firDS)
{
firDS->Close();
firDS->SelectSQL->Text = txt;
firDS->Open(); //during debugging, exception occurs in this line
int count = 0;
while(!firDS->Eof)
{ count++;
firDS->Next();
}
return count;
}
Any ideas what why it happens?
Thanks in advance
There is much pain in your future.
Anyway, the problem you're having is with the database connection. There's a field in your database called "Function" that holds a string. This field came across as a String with the ancient database driver that this program originally used. Your shiny, new database driver is telling VCL to expect such things as Unicode, and VCL doesn't like to shove such things into plain Strings, so it expects you to have a WideString ready in which to shove it.
Fortunately, there are ways of beating VCL into submission. What you want to do, since you surely don't want to rewrite half the application by changing TIBDataSet, is to tell the connection not to bother with Unicode. In order to do this, you have to set up the TSQLConnection object with UseUnicode=false, which I hope (I have no way of testing VCL code anymore) should look something like this:
connection->Params->Add("UseUnicode=false");
Where connection is the TSQLConnection object. I think you have to do this before connecting to the database.
If that doesn't work, see if you can configure the database driver to not use Unicode.
Problem solved - this one field Function has other type in C++ Builder design view - it was TStringField, and rest fields has TIBStringField...
I am trying to use an ActiveX control in my program.
QAxWidget* mAX = new QAxWidget();
mAX->setControl("{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}");
I know that there is a function:
put_ChannelType(long newValue)
But when I try to execute it:
mAX->dynamicCall("put_ChannelType(long)",2);
mAX->dynamicCall("put_ChannelType(int)",2);
mAX->dynamicCall("put_ChannelType(long)",QVariant(2));
mAX->dynamicCall("put_ChannelType(int)",QVariant(2));
I get:
QAxBase: Error calling IDispatch member put_ChannelType: Bad parameter count
Any idea what is going wrong ?
EDIT:
Weird thing is if I call
mAX->dynamicCall("put_ChannelType()");
I do not get any error message...
EDIT 2:
This also fails (as Constantin suggested)
QList<QVariant> varlist;
varlist << (int)1;
mAX->dynamicCall("put_ChannelType(int)",varlist);
Got this solved using the generateDocumentation() function.
I was using this ActiveX control in another application, but an MFC one.
It seems the function names I was referring to (which were in a machine generated IDispatch wrapper class created by VS) were not the same as the ones Qt listed.
i.e. put_ChannelType is actually SetChannelType...
Maybe this is just a version issue ?
Anyways, important part is knowing that generateDocumentation() can list you all the functions you can call with dynamicCall.
Is it OK?
mAX->dynamicCall("put_ChannelType(const QVariant &)", (long)2);
I want to use Google's Javascript Engine V8 in a project, and attempted to write a wrapper class for the engine. Parts of the Code are copied from samples/shell.cc, from the V8 Distribution.
However, it just aborts with a Segmentation fault, and I can't figure out why, although the problem is happening around v8::internal::Top::global_context() (due to an invalid context, which appears to be NULL).. The code itself looks fine to me, but maybe I did something incredibly stupid :-).
The Segmentation fault in my Code happens in v8::Script::Compile.
Code in Question (Updated): https://gist.github.com/4c28227185a14bb6288c
Thanks to Luis G. Costantini R.'s Answer, there is no longer a problem in Set (It doesn't abort anymore), however, exposed names are still not available and will result in a ReferenceError...
Thy to change v8::Context::Scope context_scope(context); from the constructor (line 134) to internal_executeString (before script = v8::Script::Compile(source, name);). That because the destructor of the class v8::Context::Scope exits from the context.
I changed the method addFunction:
void addFunction(const std::string& fname, v8::InvocationCallback func)
{
v8::HandleScope handle_scope;
std::cout << "before ::Set()" << std::endl;
v8::Context::Scope context_scope(context);
context->Global()->Set(v8::String::New(fname.c_str()),
v8::FunctionTemplate::New(func)->GetFunction());
std::cout << "after ::Set()" << std::endl;
}
The function must be added to the global object of the context used to execute the script. There is an excellent tutorial (in two parts) of V8:
http://www.homepluspower.info/2010/06/v8-javascript-engine-tutorial-part-1.html
and
http://www.homepluspower.info/2010/06/v8-javascript-engine-tutorial-part-2.html
If you try to create an instance of JavaScript Function (FunctionTemplate::GetFunction()) or JavaScript Object (ObjectTemplate::NewInstance()) before entering the context (via Context::Scope), you get the segmentation fault. The reason: there is no JavaScript context available and both Function and Object always exist in a JavaScript execution context only. As per V8 documentation:
Function:
A JavaScript function object (ECMA-262, 15.3).
Object:
A JavaScript object (ECMA-262, 4.3.3).
The stack backtrace is almost useless unless I download all the source and try to build it myself, so... :)
Change js.executeString("1+1", true, false); to js.executeString("1+1", true, true); and see what the exception handler tells you?
Looks like you just got stung by this bug, that is if you have not already taken note of it. Perhaps submit another report since the referenced one looks old. Perhaps dig a little deeper and investigate the stack frame at every function call until the Segmentation Fault is received, you could either find a work around or the fix for this bug :)
I had a similar segmentation fault and the problem turned out to be the following. I was creating a new thread and attempting to create an object template and object in that thread. Unfortunately it seems that if you create a thread, you need to make sure that you enter a v8::Context again in order to do such things.
I got it working by passing a Handle to the v8::Context::Calling to the newly created thread and entered it in the new thread by using a scope.
I wrote this here as it is the only useful thing that comes up when I do a google search for the segmentation fault.
So I'm trying to make use of a GtkSourceView in C++ using GtkSourceViewmm, whose documentation and level of support give me the impression that it hasn't been very carefully looked at in a long time. But I'm always an optimist :)
I'm trying to add a SourceView using some code similar to the following:
Glib::RefPtr<gtksourceview::SourceLanguageManager> source_language_manager = gtksourceview::SourceLanguageManager::create();
Glib::RefPtr<gtksourceview::SourceLanguage> source_language = Glib::wrap(gtk_source_language_manager_guess_language(source_language_manager->gobj(), file, NULL));
Glib::RefPtr<gtksourceview::SourceBuffer> source_buffer = gtksourceview::SourceBuffer::create(source_language);
gtksourceview::SourceView* = m_source_view = new gtksourceview::SourceView(source_buffer);
m_vbox.pack_start(*m_source_view);
Unfortunately, it spits out the warning
(algoviz:4992): glibmm-WARNING **:
Failed to wrap object of type
'GtkSourceLanguage'. Hint: this error
is commonly caused by failing to call
a library init() function.
and when I look at it in a debugger, indeed the second line above (the one with the Glib::wrap()) is returning NULL. I have no idea why this is, but I tried to heed the warning by adding Glib::init() to the begining of the program, but that didn't seem to help at all either.
I've tried Google'ing around, but have been unsuccessful. Does anyone know what Glib wants me to init in order to be able to make that wrap call? Or, even better, does anyone know of any working sample code that uses GtkSourceViewmm (not just regular GtkSourceView)? I haven't been able to find any actual sample code, not even on Google Code Search.
Thanks!
It turns out, perhaps not surprisingly, that what I needed to init was:
gtksourceview::init();
After this, I ran into another problem with one of the parameter to gtksourceview::SourceLanguageManager, but this was caused by a genuine bug which I subsequently reported and was promptly fixed. So everything's working great now!
I use gtkmm. Typically you have to initialize things with something like :
_GTKMain = new Gtk::Main(0, 0, false);
Of course do not forget :
delete _GTKMain;
Check here for details :
http://library.gnome.org/devel/gtkmm/2.19/classGtk_1_1Main.html
(Sorry but the link option does not work ...)