I have a project in Qt Creator and am trying to compile a static release. To do so, I have added "static" to my "CONFIG" option in my .pro file.
After rebuilding all the files, I get a folder named "release" with an executable and a few other files inside of it. When trying to execute the generated file, I get an error that reads as such:
"The procedure entry point __cxa_throw_bad_array_new_length could not be located in the dynamic link library C:\Qt\5.5\mingw492_32\bin\QtCore.dll"
This error message remains whether I use mingw 5.5.0 or 5.4.2 to compile the files.
Using dependency walker and coping the "correct" QT dll files also does not resolve the problem.
What I know already: This error happens to people who copy the wrong QTCore.dll to their project folder. However, since I am not copying any .dll files, I don't know how to use this information to my advantage.
In conclusion, my question is: How do I stop this error from occurring? Moreover, is there a better way to statically compile a qt application?
To build static release of your application you basically need two things:
1) add
CONFIG += static
in your .pro file (you did it) and don't copy any Qt dlls.
2) you need to build static Qt
https://wiki.qt.io/Building_a_static_Qt_for_Windows_using_MinGW
By default Qt is installed prepared for dynamic linking, this is why you need to build static Qt on your own.
You may want to look also at this great Q&A:
Qt static linking and deployment
but it deals mainly with Qt4. Idea is the same.
After you will build static Qt you will need to rebuild your application. And don't copy any Qt dlls.
Related
I created a simple notepad file using Qt.
The program does run when in Qt creator.
However, when I navigate to the debug folder, the created executable file does not run without DLLs.
I've read online that this is can happen and all that is required is that the respective DLLs be copied to the location of the exe file. However... the error messages identify DLLs that my machine does not have.
I get and error message for the following DLL files.
Qt5Cored.dll, Qt5Widgetsd.dll, QtPrintSupportd.dll
I do not have the DLLs above. I do however have the dll files below. Which do not have the added 'd' before the extension.
Qt5Core.dll, Qt5Widgets.dll, QtPrintSupport.dll
Any help provided would be much appreciated.
Thank you in advance!
First i can't think of any reason you would want to copy (preparing for an installer) the dependencies for the debug build of your application, the debug is not a build that you want to deploy, use the release build for deployment.
Now, that being said, you definitely have the dll's, otherwise your debug build won't run from Qt Creator, you are just not looking in the right path for those dlls.
The path where you find the dll is something like: C:\Qt\5.12.3\msvc2017_64\bin
notice that there can be many Qt versions installed and for different targets (example android), so the right way to find the dlls is: QT_INSTALL_PATH / QT_VERSION / COMPILER_VERSION _ARCHITECTURE / bin, so the sample path i provided is Qt version 5.12.3 build with Visual Studio 2017's compiler and it is a 64 bit build. In that path you will find the right dlls: Qt5Core.dll (the release build), Qt5Cored.dll (debug) and so on for all the Qt modules.
Side note: you most likely looked into the folder where Qt Creator .exe is located, there you will find only the Qt dlls that are needed for Qt Creator to work, you are not supposed to use those dlls to deploy your application (those might be built with a different compiler than what you are using and even cause crashes for your application, because of incompatible abi)
I would like to compile staticly my Qt 5 application. I used this link :
Qt static linking and deployment
The problem is that I don't know where is the "configure" file or how to generate it ?
ps: the old option to add "CONFIG = static" in the .pro file doesn't work with Qt5
You have to first compile the whole Qt library statically. Then, use that configuration in your projects. Then, your application will be statically compiled.
Qt (when using qmake) takes the compilation configuration from its qmakespec, which is defined during compilation of the Qt library. This includes all the parameters that are used by default.
Keep in mind that this has a learning curve. You have to try and fail a few times. It'll cost you some time to get this right. That link I provided should make this effort easier.
The problem is that I don't know where is the "configure" file or how to generate it ?
QMake make use of several type of files:
.pro
.pri
.prf
The most common is the .pro used for pro-jects. You can find/create it at the root of your project directory.
Creating a QtCreator project will automatically generate one. Be aware that there is also the qbs alternative.
the old option to add "CONFIG = static" in the .pro file doesn't work with Qt5
CONFIG *= static still works, are you sure about any other issue somewhere else?
CONFIG = static will override any previous value, using the * will append the new value without deleting previous configurations. I suggest you to use 'message( $$CONFIG)' to ensure the content is correct.
I am new to QT Creator coming from Visual Studio. I have a session with two projects in it. One is a DLL with some classes that I intend to use for other purposes. The other is an executable console app that uses some of the classes from the DLL.
I currently have these two projects side by side in QT Creator. I can include the header files from the DLL in my EXE project using relative paths "../MyPrject/header.h". But how do I get QT Creator to link and then copy the DLL into the executable debug folder for debugging.
Am I doing this all wrong? Is there a better way? If it includes adding code to the .pro file, please include a link so that I can learn more.
You should make some dependencies between this projects.
opening both projects - you have done.
on editor view, right click on exe-project and select add library...
follow creator hints to add it.
2nd option: you can make subprojects. follow QtCreator: Creating Projects from documentation (help view in Qt Creator)
GwyenBleidD provided a good starting point for including DLLs.
I however, have made a habit out of modifying the .pro file directly here and honestly I prefer to modify the .pro file in the event that something goes haywire.
Suppose I wanted to use the winsock DLL.
In the .pro file, I'd first specify the .dll's corresponding .lib file:
# WinSock2 library (ws2_32.lib file)
LIBS += -lws2_32
# Path to the WinSock2 library
LIBS += -L"c:/mylibraries/"
Additionally, you'll need to specify the include path to the header files here:
INCLUDEPATH += "c:/Program Files (x86)/Microsoft Visual Studio 10.0/VC/INCLUDE"
Thirdly, in my code I'd have to make sure to include the headers for it:
// I ASSUME it'll be found under something like the
// Visual Studio/VC/INCLUDE directory mentioned above.
#include <winsock2.h>
Lastly, you need to ensure that your application can find the .dll file, typically pointed to using the %PATH% environment variable.
With regards to your setup, I'd make sure that your sub-projects are configured so that the library compiles FIRST (obviously). And then ensure that the LIBS variable in your .Pro project points correctly to your .lib destination according to the build configuration (debug|release).
Qt's PRO (qmake) isn't as terrible as some make it out to be. Just give it a solid half-hour to an hour and you'll get the hang of it. I assume though that you have a solid understanding of libs and DLLs and what not.
http://qt-project.org/doc/qt-5.0/qtdoc/qmake-manual.html
The right way is to switch on CMake based project and keep exe and dll within one root project. The main benefit of this decision is IDE independent approach: you can use Qt Creator, CLion, Visual Studio without any changes in project definition. As the start point consider to see the example project https://github.com/anatoly-spb/cmake_exe_dll
When running my Visual Studio C++ application debug version through VS2010 by Project Only > ProjectName the generated exe runs well. However when I generate a release version and go to the folder where the exe is created I get the following error:
The application was unable to start correctly (0xc000007b). Click Ok to close the application
The files in the folder is only the exe file whereas my project uses various boost libraries.
Is it possible that its giving this message because of the missing boost dlls ? Is there a way to make the compiler paste all the necessary dlls in the exe folder.
Is there any way to launch the release version from VS2010 like we have for the debug version as in Debug >> Start new instance
I hate when that happens. It could be the fact that its missing the bloost DLL's: the easiest way to fix this is to add the folder to the Path environment variable. Sadly enough, we don't have enough information from your post to confirm that this is the problem. Common other problems include: you are linking to libraries that were built for a different architecture/are using a different runtime library, you are missing other 3rd party dlls, the .lib file you used in the linker is pointing to a different version of the code than the dll you are pointing to...the list goes on.
As for copying the dlls at runtime, you can do this using the custom build events [http://msdn.microsoft.com/en-us/library/e85wte0k%28v=vs.80%29.aspx]. Just write a batch script that copies the dlls as a "Post Build Event" and you should be good to go, but I'd suggest the Path way first.
I am trying to build a .dll that uses the QtCore4 and QtGui4 .dll files. However, I want both Qt .dll files to be linked non-statically. I have read a lot about .pro files and static linking but no one seems to talk about dynamic linking with Qt .dll's. How do I ensure that the qt dlls are built for dynamic linking?
I am having problems that there seems to be two instances of the dll's in my app, one in the app that uses my dll, and then one for the dll itself, so when I try and get a window handle the code inside my dll can't 'see' it; disjoint qtwidget sets is the phrase often used.
Any suggestions?
Unless you added the keyword 'static' to your configuration parameters, the Qt libraries should be already building as dynamic link libraries. That is the default configuration.
The dll extension means Dynamically Linked Library. This means that if you compile the library as a dll, it will always be suitable for dynamic linking.
(If you build a library for statical linking, that has a different extension and requires different config.)
In Qt projects, dynamic linking is the default option. You don't need to do anything to achieve it.