sasume:~/test$ ls
mmain.cpp mmainform.cpp mainform.h
sasume:~/test$ cat main.cpp
#include "mainform.h" 
 
#include <QApplication> 
 
int main(int argc, char* argv[]) 
{ 
    QApplication app(argc, argv); 
        mainform mf; 
        mf.resize(400,400); 
        mf.show(); 
    return app.exec(); 
}
sasume:~/test$ cat mainform.h
#ifndef MAINFORM_H_INCLUDED 
#define MAINFORM_H_INCLUDED 
 
#include <QMainWindow> 
 
class mainform : public QMainWindow 
{ 
        Q_OBJECT 
 
public: 
        mainform(QWidget *parent = 0); 
}; 
 
#endif // MAINFORM_H_INCLUDED
sasume:~/test$ cat mainform.cpp
#include "mainform.h" 
 
mainform::mainform(QWidget *parent): QMainWindow(parent) 
{ 
        this->setWindowTitle("test"); 
        return; 
}
sasume:~/test$ qmake -project
sasume:~/test$ qmake
sasume:~/test$ make
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I../kde/src/qt-copy/mkspecs/linux-g++ -I. -I../qt-copy/include/QtCore -I../qt-copy/include/QtCore -I../qt-copy/include/QtGui -I../qt-copy/include/QtGui -I../qt-copy/include -I. -I. -I. -o main.o main.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I../kde/src/qt-copy/mkspecs/linux-g++ -I. -I../qt-copy/include/QtCore -I../qt-copy/include/QtCore -I../qt-copy/include/QtGui -I../qt-copy/include/QtGui -I../qt-copy/include -I. -I. -I. -o mainform.o mainform.cpp
/home/kde-devel/qt-copy/bin/moc -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I../kde/src/qt-copy/mkspecs/linux-g++ -I. -I../qt-copy/include/QtCore -I../qt-copy/include/QtCore -I../qt-copy/include/QtGui -I../qt-copy/include/QtGui -I../qt-copy/include -I. -I. -I. mainform.h -o moc_mainform.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I../kde/src/qt-copy/mkspecs/linux-g++ -I. -I../qt-copy/include/QtCore -I../qt-copy/include/QtCore -I../qt-copy/include/QtGui -I../qt-copy/include/QtGui -I../qt-copy/include -I. -I. -I. -o moc_mainform.o moc_mainform.cpp
g++ -Wl,--no-undefined -o test main.o mainform.o moc_mainform.o    -L/home/kde-devel/qt-copy/lib -lQtGui -L/home/kde-devel/qt-copy/lib -L/usr/X11R6/lib -lpng -lSM -lICE -pthread -pthread -lXi -lXrender -lXrandr -lfreetype -lfontconfig -lXext -lX11 -lQtCore -lz -lm -pthread -lgthread-2.0 -lrt -lglib-2.0 -ldl -lpthread
sasume:~/test$

(j'utilise Qt 4.4)