QtPlugin and undefined symbol

FilePluginInterface.h

Code:

#ifndef FILEPLUGININTERFACE_H
#define FILEPLUGININTERFACE_H
 
#include "Geocache.h"
 
#include <QtPlugin>
#include <QIODevice>
#include <QString>
#include <QList>
 
class FilePluginInterface {
public:
    virtual ~FilePluginInterface() {}
 
    virtual const char *getName() const throw() = 0;
    virtual const char *getVersion() const throw() = 0;
    virtual const char *getAuthor() const throw() = 0;
    virtual const char *getAuthorEmail() const throw() = 0;
    virtual bool isValid(QIODevice *source) = 0;
 
    virtual QList<Geocache*> getAll(QIODevice *source) = 0;
};
 
Q_DECLARE_INTERFACE(FilePluginInterface, "com.Something.Plugins.FilePlugin/1")
 
#endif // FILEPLUGININTERFACE_H

GeocachingComGpx.cpp

Code:

#include "../../../src/FilePluginInterface.h"
 
class GeocachingComGpx : public QObject, public FilePluginInterface {
    Q_OBJECT
    Q_INTERFACES(FilePluginInterface)
 
public:
    const char *getName() const throw();
    const char *getVersion() const throw();
    const char *getAuthor() const throw();
    const char *getAuthorEmail() const throw();
 
    bool isValid(QIODevice *source);
 
    QList<Geocache*> getAll(QIODevice *source);
};
 
const char *GeocachingComGpx::getName() const throw()
{
    return "Geocaching.com GPX Files";
}
 
const char *GeocachingComGpx::getVersion() const throw()
{
    return "0.1.0";
}
 
const char *GeocachingComGpx::getAuthor() const throw()
{
    return "James Marshall Hendrix";
}
 
const char *GeocachingComGpx::getAuthorEmail() const throw()
{
    return "jimi@hendrix.com";
}
 
bool GeocachingComGpx::isValid(QIODevice *source)
{
    Q_UNUSED(source);
    return true;
}
 
QList<Geocache*> GeocachingComGpx::getAll(QIODevice *source)
{
    Q_UNUSED(source);
    return QList<Geocache*>();
}
 
Q_EXPORT_PLUGIN2(GeocachingComGpx, GeocachingComGpx);

GeocachingComGpx.pro

Code:

NAME = GeocachingComGpx
VERSION = 0.1.0
HEADERS += ../../../src/FilePluginInterface.h
SOURCES += GeocachingComGpx.cpp
 
TEMPLATE = lib
TARGET = $${NAME}
DESTDIR = ../../../bin/plugins/file/
DEPENDPATH += $$PWD
INCLUDEPATH += $$PWD
CONFIG += plugin
 
target.path = /usr/share/something/plugins/file/
 
INSTALLS += target

And when I'm trying to load a plugin:

Code:

QStringList files = path.entryList(QDir::Files);
 
        for (QStringList::iterator it2 = files.begin(); it2 != files.end(); it2++) {
            QPluginLoader pluginLoader(path.absoluteFilePath(*it2));
            QObject *plugin = pluginLoader.instance();
 
            if (plugin) {
                filePlugins.append(qobject_cast<FilePluginInterface*>(plugin));
                qDebug() << "Loaded plugin" << filePlugins.last()->getName()
                         << filePlugins.last()->getVersion();
            } else {
                qDebug() << pluginLoader.errorString();
            }
        }

pluginLoader.errorString() gives me

Code:

/some/nice/path/bin/plugins/file/libGeocachingComGpx.so: undefined symbol: _ZTV16GeocachingComGpx

_ZTV16GeocachingComGpx seems to be the symbol of my plugin's class (I looked into binary, methods symbols are prepended by it). Why it's missing from the binary? And if it's not, what's going on then?

Thanks for your time