Linker Error

[ankurjain]

Hi Guys,
i m here again for ur help ...

i've prepared a dll, that provides a table in the main program and the excel like operations (cut,copy,paste ....)

my dll is compiling working fine, but when i use that dll warnings and error come.

please look at the following compiler error :

Compiling...
moc_QGrid.cpp
warning C4273: 'public: static struct QMetaObject const QGrid::staticMetaObject' : inconsistent dll linkage.  dllexport assumed.
error C2491: 'QGrid::staticMetaObject' : definition of dllimport static data member not allowed
warning C4273: 'metaObject' : inconsistent dll linkage.  dllexport assumed.
warning C4273: 'qt_metacast' : inconsistent dll linkage.  dllexport assumed.
warning C4273: 'qt_metacall' : inconsistent dll linkage.  dllexport assumed.
Error executing cl.exe.
 
program.exe - 1 error(s), 4 warning(s)

Compiling...
moc_QGrid.cpp
warning C4273: 'public: static struct QMetaObject const QGrid::staticMetaObject' : inconsistent dll linkage.  dllexport assumed.
error C2491: 'QGrid::staticMetaObject' : definition of dllimport static data member not allowed
warning C4273: 'metaObject' : inconsistent dll linkage.  dllexport assumed.
warning C4273: 'qt_metacast' : inconsistent dll linkage.  dllexport assumed.
warning C4273: 'qt_metacall' : inconsistent dll linkage.  dllexport assumed.
Error executing cl.exe.

program.exe - 1 error(s), 4 warning(s)

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my pro file for the main project:

######################################################################
# Automatically generated by qmake (2.00a) Mon Jan 2 11:42:05 2006
######################################################################
 
TEMPLATE = app
TARGET += program
DEPENDPATH += .  ui Uidata
INCLUDEPATH += . ../header/
 
# Input
HEADERS += xxx.h yyy.h
FORMS += Uidata/xxx.cpp Uidata/yyy.cpp
SOURCES += xxx.cpp yyy.cpp
RESOURCES += Uidata/tds.qrc
QT        += xml
UI_DIR = ui
MOC_DIR = moc
OBJECTS_DIR = obj
LIBS = ../dll/release/QGrid.lib

######################################################################
# Automatically generated by qmake (2.00a) Mon Jan 2 11:42:05 2006
######################################################################

TEMPLATE = app
TARGET += program
DEPENDPATH += .  ui Uidata
INCLUDEPATH += . ../header/

# Input
HEADERS += xxx.h yyy.h
FORMS += Uidata/xxx.cpp Uidata/yyy.cpp
SOURCES += xxx.cpp yyy.cpp
RESOURCES += Uidata/tds.qrc
QT        += xml
UI_DIR = ui
MOC_DIR = moc
OBJECTS_DIR = obj
LIBS = ../dll/release/QGrid.lib

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my QGrid.h file is something like this :

#ifndef QGRID_H
#define QGRID_H
#include <QtCore/qglobal.h>
#include <QTableWidget>
 
 
#ifdef Q_OS_WIN
#  ifdef BUILD_QGRID
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT
#endif
 
#include <QAction>
 
class QGRID_EXPORT QGrid : public QTableWidget
{
	Q_OBJECT
public:
	QGrid(int c,int r,QWidget *parent = 0);
	QGrid(QWidget *parent = 0);
 
private:
	QAction *cutAct;
	QAction *copyAct;
	QAction *pasteAct;
 
public slots:
	void cut();
	void copy();
	void paste();
public:
	void setUpContextMenu();
	void createActions();
};
#endif

#ifndef QGRID_H
#define QGRID_H
#include <QtCore/qglobal.h>
#include <QTableWidget>


#ifdef Q_OS_WIN
#  ifdef BUILD_QGRID
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT
#endif

#include <QAction>

class QGRID_EXPORT QGrid : public QTableWidget
{
	Q_OBJECT
public:
	QGrid(int c,int r,QWidget *parent = 0);
	QGrid(QWidget *parent = 0);

private:
	QAction *cutAct;
	QAction *copyAct;
	QAction *pasteAct;

public slots:
	void cut();
	void copy();
	void paste();
public:
	void setUpContextMenu();
	void createActions();
};
#endif

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i m not getting the cause of the error. i generated the preprocessor files to chk if some problem in macro expansion, but it expands fine .... in dll it expands to __declspec(dllexport) and in the main project it expands to __declspec(dllimport)

when i keep the .cpp and .h file in the main project, this error won't come.

i m using MSVC++ for sompiling the project.

Please help guys, i m stuk for last 1 week in this ...

[jacek]

It looks like moc is run on your library headers.

[ankurjain]

hi,
thanx 4 replying. the problem is solved, the errors are gone, but i don't know y & how ..
i followed the method prescribed by ChristianEhrlicher posted in my other thread, and did like this :

#ifdef BUILD_QGRID
#  ifdef Q_CC_MSVC
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT 
#endif

#ifdef BUILD_QGRID
#  ifdef Q_CC_MSVC
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT 
#endif

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this way it compiles error free.
i earlier used the code (below) :

#ifdef Q_OS_WIN32
#  ifdef BUILD_QGRID
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT
#endif

#ifdef Q_OS_WIN32
#  ifdef BUILD_QGRID
#    define QGRID_EXPORT Q_DECL_EXPORT
#  else
#    define QGRID_EXPORT Q_DECL_IMPORT
#  endif 
#else
#	 define QGRID_EXPORT
#endif

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is there much difference in these codes ? as per logic, both must work fine ....
and ya the error was compiler error not the linker's, but now i can't edit the topic

thanx