Suddenly getting 'undefined ref to 'WinMain@16'

[Doug Broadwell]

After doing a:

qmake -project "CONFIG += debug", "win32: CONFIG += console"
qmake n2.pro

(which I've done many times in the past, I'm getting:

make -f Makefile.Debug
make[1]: Entering directory `C:/Data/Qt/mverse/n2'
g++ -mthreads -Wl,-enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc -Wl,-subsystem,console -o "debug\n2.exe" debug\q
extserialbase.o debug\qextserialport.o debug\win_qextserialport.o -L"c:\Data\Qt\4.2.3\lib" -lQtGuid4 -lQtCored4
C:/Data/Qt/MinGW/bin/../lib/gcc/mingw32/3.4.2/../../../libmingw32.a(main.o)(.text+0x106):main.c: undefined reference to `WinMain@16'
collect2: ld returned 1 exit status
make[1]: *** [debug\n2.exe] Error 1

I'm not sure how to go about debugging this.

Thanks, Doug

[pgorszkowski]

Can you show us your main.c file?

[JPNaude]

Hi,

I've been getting similar types of errors, don't have a message now, but in my case the problems are also in mingw libraries or in qt libraries. I've only experienced this with Qt Creater 0.9 Alpha, so I assumed there's something wrong with the libraries shipped with it.

I haven't tried to solve it yet though,
Cheers
Jaco

[jpn]

Adding or removing "CONFIG += console" requires rebuilding the application (or at least the source file containing main() function). Unfortunately rebuilding doesn't happen automatically because the source file doesn't change.

[Doug Broadwell]

Here's the code for my main.cpp:

#include <QApplication>
#include <QtGui>
#include "MainWindow.h"
#include "comm.h"
#include "state.h"
#include "error.h"
#include "main.h"
 
#include "ctl_cfg_assoc.h"
 
 
 
//- GLOBAL OBJECT POINTERS -//
 
MainWindow*  mw;
QScrollArea* sa;
 
 
QByteArray qbaEmpty;
 
 
 
 
//----------------------------------------------------------------------------------
//  REIMPLEMENTATION OF QApplication::notify() TO CATCH OTHERWISE UNCAUGHT ERRORS  |
//---------------------------------------------------------------------------------------------------------
//  *FIXME*  We want to remove this for production.
 
qMyApp::qMyApp( int argc, char* argv[] ) : QApplication( argc, argv ) {};
 
qMyApp::~qMyApp() {};
 
//---------------------------------------------------------------------------------------------------------
 
bool qMyApp::notify( QObject* qoReceiver, QEvent* qeEvent ) {
 
    try {
 
	return QApplication::notify( qoReceiver, qeEvent );
 
    } catch( Fatal_Error& E ) {
 
	qDebug() << "\n" << E.Error_String() << "\n";
	throw;
 
    } catch( Base_Error& E ) {
 
	qDebug() << "\n" << E.Error_String() << "\n";
	throw;
 
    } catch( ... ) {
 
	qDebug("\nUnknown Error Caught\n");
	throw;
    }
};
//---------------------------------------------------------------------------------------------------------

#include <QApplication>
#include <QtGui>
#include "MainWindow.h"
#include "comm.h"
#include "state.h"
#include "error.h"
#include "main.h"

#include "ctl_cfg_assoc.h"



//- GLOBAL OBJECT POINTERS -//

MainWindow*  mw;
QScrollArea* sa;


QByteArray qbaEmpty;




//----------------------------------------------------------------------------------
//  REIMPLEMENTATION OF QApplication::notify() TO CATCH OTHERWISE UNCAUGHT ERRORS  |
//---------------------------------------------------------------------------------------------------------
//  *FIXME*  We want to remove this for production.

qMyApp::qMyApp( int argc, char* argv[] ) : QApplication( argc, argv ) {};

qMyApp::~qMyApp() {};

//---------------------------------------------------------------------------------------------------------

bool qMyApp::notify( QObject* qoReceiver, QEvent* qeEvent ) {

    try {

	return QApplication::notify( qoReceiver, qeEvent );

    } catch( Fatal_Error& E ) {

	qDebug() << "\n" << E.Error_String() << "\n";
	throw;

    } catch( Base_Error& E ) {

	qDebug() << "\n" << E.Error_String() << "\n";
	throw;

    } catch( ... ) {

	qDebug("\nUnknown Error Caught\n");
	throw;
    }
};
//---------------------------------------------------------------------------------------------------------

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//---------
//  MAIN  |
//---------------------------------------------------------------------------------------------------------
 
int main(int argc, char *argv[]) {
 
 
    //--  CREATE APPLICATION OBJECT  --//
 
    qMyApp app(argc, argv);
 
    //--  CREATE STATE OBJECT  --//
 
    Init_State();					// Must come before creating the Serial Port.
 
    //--  CREATE SERIAL PORT OBJECT  --//
 
    Init_SerialPort( 2 );				// Create COM2.
 
    //-- CREATE CtlCfgAssoc OBJECT --//
 
    Init_CtlCfgAssoc();
 
    //--  CREATE MAIN WINDOW OBJECT WITH SCROLLBARS  --//
 
    mw = new MainWindow;
    sa = new QScrollArea;
    sa->setWidget( mw );
    sa->show();
 
    //--  RUN  --//
 
    return app.exec();
}
//---------------------------------------------------------------------------------------------------------

//---------
//  MAIN  |
//---------------------------------------------------------------------------------------------------------

int main(int argc, char *argv[]) {


    //--  CREATE APPLICATION OBJECT  --//

    qMyApp app(argc, argv);

    //--  CREATE STATE OBJECT  --//

    Init_State();					// Must come before creating the Serial Port.

    //--  CREATE SERIAL PORT OBJECT  --//

    Init_SerialPort( 2 );				// Create COM2.

    //-- CREATE CtlCfgAssoc OBJECT --//

    Init_CtlCfgAssoc();

    //--  CREATE MAIN WINDOW OBJECT WITH SCROLLBARS  --//

    mw = new MainWindow;
    sa = new QScrollArea;
    sa->setWidget( mw );
    sa->show();

    //--  RUN  --//

    return app.exec();
}
//---------------------------------------------------------------------------------------------------------

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But I haven't changed anything in it from before when it was working. It seems to be an issue with 'main.c' in libmingw32.a but I don't know what it's doing.

Doug

[jpn]

As I told you, rebuild the application:

make clean
qmake
make

make clean
qmake
make

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[Doug Broadwell]

Sorry if I wasn't clear; I have rebuilt the application and still get this error.

Doug

[Doug Broadwell]

Found the problem (but not what is causing it). For some reason the 'qmake -project' is making a project file with only a subset of the header and source files in it, when I add all the files (I assume that missing the file with main() in it was causing the error) and running qmake it seems to be fine again.

Doug

[jpn]

Well, "qmake -project" is supposed to be something that you run once in the beginning of a project to generate an initial project file. It's not intended to be used to maintain the project file.