What exactly QtCreator Build/Clean makes?

Question

I am using QtCreator with CMake. In my CMakeLists.txt files I use GLOB_RECURSE QOBJECT_SOURCES "*.cpp", just to avoid editing the file when adding a new source. That time of course CMake does not changes its mind about the available files it should compile. I expected that if I use Build/Clean, it will clean caches and when I re-compile the project, my new source files will be found. However, QtCreator neglects the newly added file. I need to clean the build directory manually, and run cmake ..; make. So, what exactly Build/Clean makes and what is the difference versus Build/Rebuild? Is there anything in QtCreator, I can make my new file known to the compiler?

ClassicOcean ClassicOcean · Accepted Answer · 2016-12-23T20:22:48

When one push "Build > Clear CMake Configuration", the file CMakeCache.txt and the directory CMakeFiles from the Build directory are deleted :

https://github.com/qtproject/qt-creator/blob/master/src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp

    m_clearCMakeCacheAction [...] "Clear CMake Configuration"
    [...]
    connect(m_clearCMakeCacheAction [...] clearCMakeCache(SessionManager::startupProject());

https://github.com/qtproject/qt-creator/blob/master/src/plugins/cmakeprojectmanager/builddirmanager.cpp

void BuildDirManager::clearCache()
{
    auto cmakeCache = Utils::FileName(workDirectory()).appendPath(QLatin1String("CMakeCache.txt"));
    auto cmakeFiles = Utils::FileName(workDirectory()).appendPath(QLatin1String("CMakeFiles"));

    const bool mustCleanUp = cmakeCache.exists() || cmakeFiles.exists();
    if (!mustCleanUp)
        return;

    Utils::FileUtils::removeRecursively(cmakeCache);
    Utils::FileUtils::removeRecursively(cmakeFiles);

    forceReparse();
}

What version of QtCreator and CMake are you using ?

I suspect the behavior you described is previous to QtCreator 4.1 (Or at least I remember something similar happened me before I jumped to version 4.1, available at QtCreator snapshots ).

Just in case, you should try latest and see if that solve your problem, because I am using QtCreator 4.2 and CMake 3.7 (and previously QtCreator 4.1 and Cmake 3.5), and I do not see what you describe.

I setup files like you (Although CMake developers do not recommend it). I mean that in CMakeList.txt I mostly add a GLOB ( or GLOB_RECURSE if I want scan recursively the pointed directories).

That way, after one create a new file in those directories, in Qt Creator just it's needed to push "Build > Run CMake", or at editor modify CMakeList.txt with a blank space plus a CTRL+S (if one have activated 'Autorun CMake' at "Options > Build & Run > CMake"). Both actions update the listed files tree with the new files, ready for a Build and Run (CTRL+R).

From my humble point of view, I think it's the more comfortable way when one is constantly creating and renaming files in a new project ( In my case I add *.h and *.hpp also, for be able to see those files listed at project ).

What exactly QtCreator Build/Clean makes?

2 Answers