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Qtcreator and 64 bits developpement on windows 7

  • Hi,

    after some googling and test'n'error with qt/qtcreator/mkspecs sources, I can't obtain a "SDK" to devel 64bits apps for windows.
    Using mingw-w64 would be a plus, but well if for the moment VS2008 works it will be fine ;)

    I don't say that it's not possible, nor that the information is not available on the web... it's just very confused for a not so "very high tech" subject : Is there a complete howto explaining the state of the art on using Qt/QtCreator on x64 ?

    As you could imagine, i'm not an expert with compiler, compiling all the framework, patches and so on... I'm just a "scientist" profile trying to develop more arguments to convince collegues in my enterprise that Qt is the good choice, cause of the quality and the richness of this framework AND cause of the multi-plateforme possibilities.

    Can 64 bits devel under windows be a "hacker" trick for more time ?

  • As far as I know there is no manual yet because it isnt even fully supported.

    but what I did was compiling Qt and Qt-Creator myself for 64Bit and everything works fine.

  • You can use QtCreator 32bit for developing 64bit application, but you must build separate 64 version of qt framework.

  • but you cant use debugging helpers for 64bit application in a 32bit Qt-Creator. When you build Creator with 64Bit it also demands for the 64bit debugging helpers

  • maybe, I use Creator for writing code on windows, but I use MSVC for debuging on Windows, because Creator do it slow now :(

  • thanks for your replies ;)

    but what mkspecs do you use ? a custum one I presume ? I don't find a win64 one in the mkspecs dir.
    And how do you said in your .pro, compile for win64?
    can define in your pro, a config for win32 and a config for win64?

    sorry for, perhaps, the newby questions, but I'm sure that a lot of silent will find this very useful ;)
    perhaps someone can post a .pro exemple

  • oups, forget a point,
    when you said compile 64bits version, you mean VS2008/2010 I suppose, not mingw-w64

  • I compiled qt64 in the Visual Studio 2005 x64 Win64 Command Prompt.
    It's enough to build qt 64.

  • ok! I'll try with 2008, the one installed in my laptop;), I'll give feedback it could be useful for someone...

    When done, idem for creator i presume
    but next, when compiling a project, you choose the qt version in the options, and qmake use the win32 mkspecs?? quite strange if yes?

    Or maybe when compil Qt for x64, new mkspecs are produced in the mkspecs dir ?

    ok, ok, I'll begin the x64 quest, trying to post here the difficulties and perhaps the solutions ;)

  • ok ok ;) not so hard!

    well, download the sources, for Qt 4.7.0 and creator 2.0.1, read the README and open a visual x64 cmd. It take long time... Generating debug and release in one shot don't work for me. If you want to compile in a specific directory, out of the source tree, you'll need perl in the PATH. I don't find how to patch the binaries to make a good package, without the original source tree write in the binaries... not useful in my case, for the moment.

    a few questions and remarks:

    • openssl: I disable the option cause this lib is not installed in my laptop. I'll try later with the binaries from "slproweb":
    • dbus: I don't know for the moment how to do. Is it possible on windows?
    • debugging helpers: I have to go in the ...\qt-everywhere-opensource-src-4.7.0\qtc-debugging-helper dir and make it "by hand" (qmake and nmake). From the creator options ui it doesn't work, and the log said ok ?? strange, but perhaps a mistake... and don't know.
    • debugging helper: debug a 32bits app with helpers on creator 64bits + CDB 64bits ... raise exception and don't work ?
    • debugging helper: infact with and without helpers, in 64 bits mode in this case, I don't see what the "plus" ;) I need to read more docs eventually
    • CDB: ok the first time it's really long to wait the loading but next times it's not so bad. from visual it's faster ok, but not so bad ;)
    • jom is a separate package, I don't try to install it, but you can find a pointer "here":
    • I'd like to know how to do that with mingw-x64, and Windows SDK 7.1 (without visual installed), I'll try to do it in my spare time, if someone have experiences about that, post it :) It's so easy with linux...
    • I don't understand why 64bits windows binaries are not proposed by Qt, and yes the windows way to jump 64bits is rock and roll, but Qt is cute cause of its portability and user friendly use....
    • I was surprised by the so many warning about conversion size_t/int in the libs sources! Ok I need to practice 64bits programming, I'm really a newbie on 64bits pitfalls, but it seems dangerous
    • If someone have some good pointers on 64 bits programming, post them !

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