On 06.10.10 22:47:15, Stephen Kelly wrote: > Hi, > > The documentation says > > > A package-specific list of components may be listed after the REQUIRED > > option or after the COMPONENTS option if no REQUIRED option is given. > > http://www.cmake.org/cmake/help/cmake-2-8-docs.html#command:find_package > > But it doesn't say why you would want to do that. At first I thought it was > to specify that only the components specified would be used to fill cmake > variables. However, find_package(Qt COMPONENTS QtCore) also results in > ${QT_QTGUI_LIBRARY} being defined for example. So then I thought maybe the > semantic is that if one of the components can not be found, the find_package > fails. So I tried find_package(Qt REQUIRED QtCore QtDoesNotExist) which > works without error. > > What am I missing? > > The reason I ask is that I finally figured out why the tests in my library > needed to be linked to QtGui, even though it only uses QtCore. > > The reason is that find_package(Qt) causes QT_GUI_LIB to be defined. Which > in turn causes QTEST_MAIN to be defined to expand to use QApplication > instead of QCoreApplication as it is if QT_GUI_LIB is not defined. > > http://qt.gitorious.org/qt/qt/blobs/4.7/src/testlib/qtest.h > > find_package(Qt REQUIRED QtCore QtScript) does not cause QT_GUI_LIB to be > defined. However, some of my targets do need QtGui, so I should specify it, > right? > > So if I do specify it I'll end up having QT_GUI_LIB defined when building my > unit tests. I could remove_definitions(-DQT_GUI_LIB), but apart from being a > BadHack(tm), it causes my unit tests which *do* require QtGui to fail at > runtime because they create QWidgets and by undeffing QT_GUI_LIB I build > them to use QCoreApplication instead of QApplication (Not allowed in Qt), so > the tests fail at runtime. > > http://gitorious.org/grantlee/grantlee/blobs/0.1/tests/CMakeLists.txt > > Is there a solution to all this? What is the point of COMPONENTS if it has > no effect on what I can include or link to? Is it possible to link some of > my tests to QtGui but not all of them and still have them all pass? Do I > need to just link my core tests to QtGui and use QApplication and quit my > complaining? > > The only way I can see to satisfy all requirements is attached. Is that > acceptable or is there a better way?
You could just use 2 find_package calls in two different subdirs. One for the case of core-libs+core-tests and the other has gui-libs+gui-tests. Unless I misunderstood something... Andreas -- Excellent day for putting Slinkies on an escalator. _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
