From QT-COM Create IDL from DLL.

[Madhura]

Expeted : Need to generate IDL file for DLL Library.

We have created a Qt Application and its output is exe, When we run idc to genrate idl from the exe it genrates properly.

1. We have created a DLL project.
2. Building the project it properly builds and generates the dll.
3. If we try to generate idl from the dll using IDC, it fails and throws the error as shown below.

Couldn't resolve 'DumpIDL' symbol in C:...\Debug\SubClass.dll
Class has no metaobject information (error in C:...\Debug\SubClass.dll)!

Our Dll project created from QT and converted to MSVC

QT CMD : idc.exe "SubClass.dll" -idl "SubClass.idl" -version 1.0

SubClass.H
#include <atlbase.h>
#include <atlsafe.h>
#include <qobject.h>
#include <qstring.h>

using namespace std;
class SWISubClass : public QObject, public QAxBindable
{
Q_OBJECT

    QAXFACTORY_DEFAULT(SWISubClass,
        "{xxxxx-xxxxx-xxxxx-xxxxx}",
        "{xxxxx-xxxxx-xxxxx-xxxxx}",
        "{xxxxx-xxxxx-xxxxx-xxxxx}",
        "{xxxxx-xxxxx-xxxxx-xxxxx}",
        "{xxxxx-xxxxx-xxxxx-xxxxx}")

public:
explicit SubClass(QObject* parent = nullptr);
~SubClass();

public Q_SLOTS:
bool OpenProject(QString projectPath);

};

SubClass.CPP
#pragma once
#include "SubClass.h"
using namespace std;

SubClass::SubClass(QObject *obj) : QObject(obj) {}

SubClass::~SubClass(){}

bool SubClass::OpenProject(QString projectPath){return true;}

[hskoglund]

Hi, for idc.exe to work on a .dll it needs to call a Qt function inside the .dll called DumpIDL().

Probably you forget to define DumpIDL as a public symbol, easiest is to create (or edit an existing) .DEF file with:

EXPORTS
    DumpIDL              PRIVATE

[JonB]

@Madhura
Hello and welcome.

I suggest you post questions about code in the General and Desktop forum, not the Jobs forum, which is for advertising/requesting jobs.

[jsulm]

@JonB I moved the topic

[Madhura]

@hskoglund

Already the def is present with DumpIDL data still we are facing this same issue

[JonB]

@Madhura If you are replying to @hskoglund please address his name not mine.

[hskoglund]

Hi, to make sure the DumpIDL symbol is present in the .dll, open a MSVC2017 CMD window:

dumpbin /exports "C:\Users\....\QtComSupportDll.dll"

DumpIDL should be seen..

Also the Qt examples like ActiveQt simple, it's an .exe not a .dll but it also uses a .DEF file to include the DumpIDL symbol. If you build it, does idc.exe work on it?