[CMake] Errors when creating a share library for Qt-application ?

[Philip Lowman]

On Thu, Jan 22, 2009 at 12:57 AM, Kermit Mei <kermit.mei at gmail.com> wrote:

> Hello, I want to use the following files under the directory gui to
> creat a share library named FreeReciteGui.so .
>
>
> $ tree
> gui
> |-- CMakeLists.txt
> |-- MainWindow.cpp
> |-- MainWindow.h
> |-- MainWindow.ui
> |-- ReciterWidget.cpp
> |-- ReciterWidget.h
> |-- ScannerWidget.cpp
> |-- ScannerWidget.h
> |-- ScannerWidget.ui
> |-- TaskModel.cpp
> |-- TaskModel.h
> |-- TesterWidget.cpp
> `-- TesterWidget.h
>
> When I link the program to this library, it always hint me:
>
> Linking CXX shared library libFreeReciteGui.so
> [ 36%] Built target FreeReciteGui
> [ 94%] Built target FreeReciteCore
> Linking CXX executable ../bin/FreeRecite-core
> gui/libFreeReciteGui.so: undefined reference to `vtable for ScannerWidget'
> gui/libFreeReciteGui.so: undefined reference to
> `ScannerWidget::complished()'
> gui/libFreeReciteGui.so: undefined reference to
> `ScannerWidget::qt_metacall(QMetaObject::Call, int, void**)'
> gui/libFreeReciteGui.so: undefined reference to `typeinfo for
> ScannerWidget'
> gui/libFreeReciteGui.so: undefined reference to `vtable for MainWindow'
> gui/libFreeReciteGui.so: undefined reference to
> `ScannerWidget::staticMetaObject'
> gui/libFreeReciteGui.so: undefined reference to
> `ScannerWidget::metaObject() const'
> gui/libFreeReciteGui.so: undefined reference to
> `ScannerWidget::qt_metacast(char const*)'
> collect2: ld returned 1 exit status
> make[2]: *** [bin/FreeRecite-core] Error 1
> make[1]: *** [src/CMakeFiles/FreeRecite-core.dir/all] Error 2
> make: *** [all] Error 2
> $
>
> But, in my model-testing with qmake, ScannerWidget and it's subclass are
> all
> work well. So I think there must be something wrong with CMakeLists.txt
> here.
> Help me point it out, please.
> The contents of CMaskLists.txt is :
>
> $ cat ../src/gui/CMakeLists.txt


Read the docs on TARGET_LINK_LIBRARIES and LINK_DIRECTORIES, there is a big
difference.

You're missing a call to TARGET_LINK_LIBRARIES(FreeReciteGui foo) (after you
call ADD_LIBRARY), where foo is the target that includes the ScannerWidget
symbols.

Also, the call to LINK_DIRECTORIES() for something within your source code
is not needed.  As long as you TARGET_LINK_LIBRARIES() to a CMake generated
target CMake will automatically include the proper paths at link time as
well as all of the dependents of the linked target (provided they are
registered with TARGET_LINK_LIBRARIES).


>
> # Include the core library.
> INCLUDE_DIRECTORIES(${FREERECITE_SOURCE_DIR}/src/core)
>
> LINK_DIRECTORIES(${FREERECITE_BINARY_DIR}/src/core)
>
> # with SET() command you can change variables or define new ones
> # here we define SAMPLE_SRCS variable that contains a list of all .cpp
> files
> # note that we don't need \ at the end of line
> SET( FRGUI_SRCS
>  MainWindow.cpp
>  ScannerWidget.cpp
>  ReciterWidget.cpp
>  TesterWidget.cpp
>  TaskModel.cpp
>  )
>
> # another list, this time it includes all header files that should be
> treated with moc
> SET( FRGUI_MOC_HDRS
>  MainWindow.h
>  ScannerWidget.h
>  ReciterWidget.h
>  TesterWidget.h
>  TaskModel.h
> )
>
> # some .ui files
> SET( FRGUI_UIS
>  MainWindow.ui
>  ScannerWidget.ui
>  )
>
> # and finally an resource file
> #SET( FRGUI_RCS
> #  ./src/rc/sample.qrc
> #  )
>
> # enable warnings
> ADD_DEFINITIONS( -Wall )
>
> # by default only QtCore and QtGui modules are enabled
> # other modules must be enabled like this:
>
> #SET( QT_USE_QT3SUPPORT TRUE )
> #SET( QT_USE_QTXML TRUE )
>
> # this command finds Qt4 libraries and sets all required variables
> # note that it's Qt4, not QT4 or qt4
> FIND_PACKAGE( Qt4 REQUIRED )
>
> # add some useful macros and variables
> # (QT_USE_FILE is a variable defined by FIND_PACKAGE( Qt4 ) that contains a
> path to CMake script)
> INCLUDE( ${QT_USE_FILE} )
>
> # this command will generate rules that will run rcc on all files from
> FRGUI_RCS
> # in result FRGUI_RC_SRCS variable will contain paths to files produced by
> rcc
> #QT4_ADD_RESOURCES( FRGUI_RC_SRCS ${FRGUI_RCS} )
>
> # this will run uic on .ui files:
> QT4_WRAP_UI( FRGUI_UI_HDRS ${FRGUI_UIS} )
>
> # and finally this will run moc:
> QT4_WRAP_CPP( FRGUI_MOC_SRCS ${FRGUI_MOC_HDRS} )
>
> # we need this to be able to include headers produced by uic in our code
> # (CMAKE_BINARY_DIR holds a path to the build directory,
> # while INCLUDE_DIRECTORIES() works just like INCLUDEPATH from qmake)
> INCLUDE_DIRECTORIES( ${CMAKE_BINARY_DIR}/src/gui )
>
> ADD_LIBRARY(FreeReciteGui SHARED
>  ${FRGUI_SRCS}
>  ${FRGUI_MOC_SRC}
>  ${FRGUI_UI_HDRS}
>  )
>
> INSTALL(TARGETS FreeReciteGui LIBRARY DESTINATION lib)
>
>
> __________________________________________________________________
>
> Thank you, very much.
>
> Kermit Mei
>
>
>
> _______________________________________________
> CMake mailing list
> CMake at cmake.org
> http://www.cmake.org/mailman/listinfo/cmake
>



-- 
Philip Lowman
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