What I've been trying to do is to link Qt libraries to my project with CMake. I would use CMake GUI to generate MakeFile and then run MinGW32-make on it, which would give me '[File Name].exe' as intended. However, whenever I run the executable file, I get a message saying:
"The procedure entry point _ZN10QArrayData10deallocateEPS_jj could not be located in the dynamic link library etc."
https://i.stack.imgur.com/JpdwK.jpg
I initially built this software using Qt Creator and QMake, so I can confirm that the program has been tested and does work, but as I have to include an API, it requires me to use CMake instead.
I have done a lot of research and experimenting mostly with the CMakeLists.txt, but unfortunately, I'm not that good at it and I kinda suspect that's where the problem lies.
Related
I follow this document Cross Compile Qt - Raspberry, and it works completly. I can cross compile simple application from qt creator. Now i want to use external libary (ID3lib). But it gets error when build project
/home/shymaxtic/Documents/FPT/Hihi/ID3tag/lib/libid3.so: error: error adding symbols: File format not recognized.
Can anyone help me?
Like Kuba Ober pointed, in order to include on you board a external library, you need to cross compile it, just like you do for your application.
Depending on the size of the library, you can either integrate it in your Qt project by creating a top level SUBDIR project, or simply cross-compile it manually, and provide the path to the cross-compiled library like you did here with LIBS += -L<path> -l<library>
When cross compiling, make sure to use the toolchain specific for your board (you already have it for Qt), and not the gcc/g++ of your desktop distribution
So basically I have the following setup:
A small test library called mylib with an according CMake file. The CMake file creates all the necessary information so that another project (which is going to be my binary) can use find_package to add the library. The library also has a install target.
A small binary called mybin again wih according CMake file which is depended on the mylib project. Using find_package I can add mylib either by specifying the location of the according myLibConfig.cmake (and myLibTargets.cmake etc.) files or by executing the install target of mylib and then letting CMake find the library itself.
Using CMake and XCode everything works like a charm. First, I configure and build the library. Second, I configure my binary project, specify the location of the library and then build it without any problems.
Now I want to do the same using CLion. My problem now is that CLion puts all the generated CMake file (which usually are placed in the build folder) in some cryptic location which can't be changed in the IDE. Now, when I want to build the mybin project I have to specify this cryptic location which seems kinda odd to me (especially because you have to find out first where CLion actually places those files).
So my question is: Is there a more convenient way to handle the described configuration? I guess this is more or less the standard use case which makes me wonder if I'm missing out on something. Being able to specify where CLion should put the generated CMake files would solve my problem I guess.
I know that i can install the library (using the install target) and then let CMake find it. The problem here is that CLion (to my understanding) doesn't support install targets and therefore I have to use (in my case) XCode to build and install the library first.
I was misunderstsanding the intention of find_package(as Tsyvarev pointed out). By using the solution proposed in this question I managed to add an install target to CLion which now allows me to conveniently build "mylib" and use it in the "mybin" project without having to configure anything manually.
I'm using CMake to build a Qt application. My project compiles, and thanks to 'fixup_bundle()', make install copies the required libraries next to my executable. Great!
Only problem is, when I execute it, I get the dreaded 'This application failed to start because it could not find or load the Qt platform plugin "windows".' error.
Indeed, manually copying qwindows.dll into a 'platforms' directory next to the executable fixes the issue. Now, how can I tell CMake to do that automatically?
Not much info from Qt :
Plugins are also available as IMPORTED targets in CMake. The Qt Network, Qt SQL, Qt GUI, and Qt Widgets modules have plugins associated. They provide a list of plugins in the Qt5_PLUGINS variable.
All right, I guess I have to play with Qt5::QWindowsIntegrationPlugin, which should be an imported target. That's where I'm lost.
I know (well, I think I know at least) that fixup_bundle() looks into the executable to find its dependencies. But despite the fact that I link my executable against QWindowsIntegrationPlugin, there is no trace of it. Therefore, no qwindows.dll copied into my output path by fixup_bundle().
Except the manual copy of the file, I couldn't find a nice CMake-friendly answer to this issue.
Thanks for your help.
Just ran into the same issue. Here is how I resolved it in my CMake install script:
# QWindowsIntegrationPlugin is part of the Gui component
find_package(Qt5 COMPONENTS Gui REQUIRED)
install(
FILES "$<TARGET_FILE:Qt5::QWindowsIntegrationPlugin>"
DESTINATION bin/platforms
)
Can someone tell me if it's possible to compile a project that works with Qt but without installing the entire sdk ? I mean, something like recompile Qt source code and link the libraries or something like this.
I know my problem is weird but I work in special conditions : I am on a linux machine and I have to work on a windows project therefore I use a distant server on windows to compile but I can't install anything on this serveur. I need an idea to have a fully portable folder with Qt who can compile without installing anything.
I hope I was clear in my explications.
Thank you for your help.
I has combined comments in answer.
You need to install compiler (e.g minGW) and Qt Library (as needed version).
You should add into environment variable 'PATH' your path to qmake and compiler.
Start terminal and move to directory with your source code of Qt project.
Run qmake and then exec make (e.g. It, for minGW, is mingw32-make).
For your case, you may choosen 2 way:
Build static Qt Library from source code and use static linking with your project.
Install Qt Library and copy libraries near your project with dynamic linking (recomended).
I am new to QT and I am enjoying the experience except for the fact I cannot manage to statically link the QT library to the output binaries. When I run the output file outside of the QT directory, I get The program can't start beacuse QtCored4.dll is missing. Obviously QT is dynamically linking their libraries and requesting a .dll I do not have. Is there a way to statically compile QT's libraries into a static binary so none of QT's dlls are required? I ask this because I am already up to 11 .dlls for my project, and I would really like to cut down the amount of files that have to be distributed with my software. Size is not a problem for me. Thanks.
I have tried adding CONFIG += static to the .pro file, but to no avail.
First off, you can't statically link Qt unless you've bought a commercial license. To do so would put you in violation of the LGPL license under which the non-commercial version is distributed. I feel your pain, I've got many, many DLL's to go with my software.
Thankfully, you probably do have the DLL's if you used the installer: you don't need to build from source, that should have been done automatically. You'll find them in Qt\Version\bin, where Qt is the directory you installed Qt, and version is the version of Qt you installed. For example, mine is found in G:\Libraries\Qt\4.7.1\bin.
I did, however, have some issues with not having one of the DLL's built - one for working with OpenGL - and performed a rebuild to do so. I've also done so when I've switched versions of Visual Studio. I think it's handy to be able to do so, it's easy, Open a terminal in the Qt directory, and execute:
configure.exe -platform XXX'
Where XXX denotes the type of build you want to perform. Valid options include win32-msvc2005, win32-msvc2008, win32-msvc2010. So I use:
configure.exe -platform win32-msvc2010'
Other options are detailed here. These instructions apply if you've downloaded the source code, however you might have to add the current directory to the path variable like so:
set PATH=%cd%\bin;%PATH%
The whole procedure should take about an hour.
You need to download the source packet of QT and compile it. It takes some time but is not really complicated.
Download and unzip QT source
Start a compiler shell (Visual Studio or mingw)
Execute configure in the QT source directory - add a flag for static compile here
execute make (Visual Studio nmake)
Wait some hours depending on the speed of your machine