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Hi. I was just wondering if it's possible to declare this variable that's used in qapplication.cpp, qapplication_x11.cpp as an extern variable and use it in my code. I need it in order to port old code I wrote for Qt3 to Qt4.
The problem is when I try to declare it as extern and then link my application, I get error that the qt_modal_stack is unresolved.
well, you can always declare it as extern.
If noone defines it, though, you end up in that error ;)
In Qt 4.4.2 such a variable is declared
therefore your code should link (if you link against the right libs.Code:
Show us your link command and the error msg, pls.
D:/Development/IDEs/MinGW/bin/mingw32-make.exe -f Makefile.Debug
mingw32-make.exe[1]: Entering directory `D:/Development/Projects/Qt4/Item_delegates'
g++ -enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc -mthreads -Wl -Wl,-subsystem,windows -o debug\Item_delegates.exe debug/ComboDelegate.o debug/main.o debug/MainWidget.o debug/Painter.o debug/moc_ComboDelegate.o debug/moc_MainWidget.o -L"d:\Development\Libraries\QT4\lib" -lmingw32 -lqtmaind -lQtGuid4 -lQtCored4
debug/MainWidget.o(.text+0x96b): In function 'ZN10MainWidget10paintEventEP11QPaintEvent':
D:/Development/Projects/Qt4/Item_delegates/MainWidget.cpp:32: undefined reference to `qt_modal_stack'
collect2: ld returned 1 exit status
mingw32-make.exe[1]: *** [debug\Item_delegates.exe] Error 1
mingw32-make.exe[1]: Leaving directory `D:/Development/Projects/Qt4/Item_delegates'
D:/Development/IDEs/MinGW/bin/mingw32-make.exe: *** [debug] Error 2
I'm using linux/X11... so I am not really sure about what the problem is here.
Have you checked, whether your Qt stuff in put into some namespace?
(There is the QT_BEGIN_NAMESPACE macro...)
Perhaps you can check if this variable is in the symbols of your lib (or object file). In linux you could use the nm command.
It appears that qt shared objects 'so' contain no symbols at all. I used nm command and it found symbols in libraries with debug name only (i.e. libQtGui.so.4.4.2.debug). Then I used "grep 'qt_modal_stack' *" command and the string was found in library libQtGui.so.4.4.2.debug. However when I tried to link with libQtGui.so.4.4.2.debug ld found no qt_modal_stack again.
maybe the symbol is not exported (newer gcc's have a "visibility" attribute...)