Qt – How to add an external .a library in Qt Creator project via GUI

qtqt-creator

I've built yamlcpp static (libyaml-cpp.a) library using Qt's mingw compiler.
Now I want to add it to my project. I use this qt doc, but Qt Creator allows to select only *.lib files not *.a files (in Choose file dialog). That's confusing because I'm using MinGW 4.4 debug configuration, not MSVC2008.

Is it possible to add *.a libraries via Qt Creator's GUI and how do I do it?
Windows 7, Qt Creator 2.3.1, Qt 4.7.4

Best Answer

As far as I know it is impossible now. The only way is to edit .pro file and add such lines:

win32 {
    #/* If you compile with QtCreator/gcc: */
    win32-g++:LIBS += -L"$$_PRO_FILE_PWD_/libs/"
    win32-g++:LIBS += -lyaml-cpp

    #/* IF you compile with MSVC:
    #win32-msvc:LIBS += /path/to/your/libMyLib.lib*/
}


macx {
    LIBS += -L"$$_PRO_FILE_PWD_/libs/"
    LIBS += -lyaml-cpp-mac
}

Related Solutions

C++ – Adding external library into Qt Creator project

The proper way to do this is like this:

LIBS += -L/path/to -lpsapi

This way it will work on all platforms supported by Qt. The idea is that you have to separate the directory from the library name (without the extension and without any 'lib' prefix). Of course, if you are including a Windows specific lib, this really doesn't matter.

In case you want to store your lib files in the project directory, you can reference them with the $$_PRO_FILE_PWD_ variable, e.g.:

LIBS += -L"$$_PRO_FILE_PWD_/3rdparty/libs/" -lpsapi

C++ – Linking with a debug/release lib with qmake/Qt Creator

The normal

debug:LIBS += ...
else:LIBS += ...

solution breaks when users naively use CONFIG += debug or CONFIG += release to switch between debug and release builds (and they do; no-one remembers to say CONFIG -= release release_and_debug before CONFIG += debug :).

This is the canonical way to scope on debug:

CONFIG( debug, debug|release ) {
    # debug
    QMAKE_LIBDIR += "path/to/debug/lib"
} else {
    # release
    QMAKE_LIBDIR += "path/to/release/lib"
}

Cf. the qmake docs.

EDIT 2013-11-17: Don't use -Lfoo in LIBS. The canonical way is to add the paths (without the -L) to QMAKE_LIBDIR.

Best Answer

Related Solutions

C++ – Adding external library into Qt Creator project

C++ – Linking with a debug/release lib with qmake/Qt Creator

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