I wrote a small app with qt and opengl (code) and I want to compile it static now.
So i downloaded Qt library and compile it static using this guide.
I added a line CONFIG += static to the pro file cd to the project location and hit:
make clean
qmake -config release
make
but I am getting several undefined references like:
qpixmapdata_gl.cpp:-1: error: undefined reference to `_imp___Z14qt_defaultDpiYv'
What I am doing wrong? Do I need to add the libs to the pro file? How do I do this and more important what libs should I use?
I tried something like this with no result:
LIBS += C:\Qt\4.7.3\bin\QtOpenGL4.dll
I see that symbol is defined in qfont.cpp, so it should be there. I would try to add:
QT += gui
in your .pro file. And I suppose you need:
QT += core
also.
EDIT: Try also to check that the symbol is included in the libQtGui.lib and the line used to compile.
Are you using the same compiler also? The mangling reported seems that of gcc. Did you compile Qt libraries with mingw or nmake?
Related
I've got a problem with include in a qmake project. In my .pro file I've got:
INCLUDEPATH += "C:\OpenCV\build\include"
and in my cpp :
#include <opencv\cv.h>
The compiler indicates an error:
Cannot open include file: 'opencv\cv.h': No such file or directory
but if I write this in my cpp:
#include "C:\OpenCV\build\include\opencv\cv.h"
it works!
I build the project from within Qt Creator. What am I doing wrong?
You have to run qmake(build->run qmake) to validate changes in the pro file.
Qt creator Adding external library (still: Cannot open include file: 'GL/glew.h')
Your problem may be related to the fact that having backslashes in naked #include directives is undefined behavior.
Do the following.
Replace your include with
#include <opencv/cv.h>
Note the forward slash!
Remove the shadow build directory that Qt Creator has made for you. You will find it above the project directory, its name begins with build-.
Rebuild the project.
Note that this takes care of rerunning qmake.
here's one of my pro files:
# Blah Application
TEMPLATE = app
CONFIG += qt console staticlib debug_and_release
QT -= gui
QT += network sql xml
TARGET = blah
CONFIG(debug, debug|release){
DESTDIR = debug
LIBS += -L../../../lib/core/debug -lcore
} else {
DESTDIR = release
LIBS += -L../../../lib/core/release -lcore
}
DEPENDPATH += . ../../lib ../../../lib/core
INCLUDEPATH += . ../../lib ../../../lib/core
# Library files
HEADERS += mtBlahRTP.h
SOURCES += mtBlahRTP.cpp
# Input
HEADERS +=
SOURCES += main.cpp
The include path points to the RELATIVE directory of my lib files. mtBlahRTP.h and mtBlahRTP.cpp are in ../../lib
I have the same question, before building or running, you should qmake(Build=>qmake) it.
My configurations for INCLUDEPATH:
INCLUDEPATH+=D:\opencv\opencv\build\include
INCLUDEPATH+=D:\opencv\opencv\build\include\opencv
INCLUDEPATH+=D:\opencv\opencv\build\include\opencv2
I ran into a similar issue and what I found is that the QtCreator IDE is not re-reading the results of qmake and updating the "Cannot open" message. You need to close the offending file and re-open it - then you'll see that it no longer displays the error.
I had to do two steps: (re-)run qmake and rebuild the whole project - only then the INCLUDEPATH setting was considered correctly. (With QtCreator 3.5 and 3.6 (Qt 5.5 and Qt 5.6) on Windows.)
The only problem you are making is incorrectly linking the OpenCV library. The other answers given here may or may not work, but I have posted on another thread a surefire way to solve this problem using the "Add Library" wizard inside Qt Creator: https://stackoverflow.com/a/51914928/10245006
I was getting the error:
canserialcomm.o: In function `CanSerialComm::CanSerialComm()':
canserialcomm.cpp:(.text+0xc1): undefined reference to `vtable for CanSerialComm'
It turns out that the cause was it wasn't able to find canserialcomm.h where that constructor is declared. This was despite me having INCLUDEPATH in the project file point to the directory containing that header file:
INCLUDEPATH += . \
..
What I had to do to fix this is explicitely specify the header file; I added:
HEADER += ../canserialcomm.h
You should use double backslashes when in windows for qt creator with msvc. like this:
INCLUDEPATH += C:\\libcurl\\libcurl-vc-x64-release-dll-ipv6-sspi-winssl\\include
this will fix the problem.
Under windows you have to eliminate the -I before each directory that is added into the INCLUDEPATH variable.
For example:
Under windows:
INCLUDEPATH += "C:\lib\boost_1_61_0" (back-slash)
Under linux & mac:
INCLUDEPATH += -I"$$(HOME)/lib/boost_1_61_0" (note the -I and forward-slash)
I'm not sure whether it depends on different qmake version or not. But after finishing qmake command, I check the Makefile and the double -I is the issue.
You need to do several things. Fist, in the .pro file, you need quotation marks two backslashes at a time, like this:
INCLUDEPATH += "C:\\OpenCV\\build\\include\\opencv\\cv.h"
You alse need a frontslash in the #include in your .cpp file like this:
#include <opencv/cv.h>
When you've done this, delete the build folder. This is the folder with a very complicated name of the type build-untitled-Desktop_Qt_5_7_0_MSVC2015_32bit-Release. Then, in the Build menu, press "Run qmake". When you've done all this, it should compile fine.
Somehow it did not work for when I had several INCLUDEPATH +=.
When I combined the stuff into a single on it suddenly worked.
I am new to Qt. Downloaded source code for a Qt application of SourceForge, and tried to build and run it. After working through a few similar problems by adding QT += statements to .pro files, I am stuck on this one:
On attempting to build in Qt Creator, I get errors saying
error: C1083: Cannot open include file: 'QPrinter': No such file or directory
I tried adding QT += printsupport to the .pro file, cleaning, and rebuilding, but that gives this error
Error: dependent '..\..\..\..\..\..\..\..\..\..\..\Qt\Qt5.1.1\5.1.1\msvc2012_64\include\QtPrintSupport\qtprintsupportglobal.h' does not exist."
When I go to C:\Qt\Qt5.1.1\5.1.1\msvc2012_64\include\QtPrintSupport, qtprintsupportglobal.h IS THERE!
You have to add QPrinter Support to your project's .pro file:
QT += printsupport
In my case the solution was to
Delete the shadow build directory and build again
after adding printsupport, as #KubaOber suggests in the comments.
Easy mistake to make: After you edit your .pro
QT += printsupport
You have to SAVE the file before your .h will be aware of it.
Because QMake will eventually be dropped in favor of CMake, here's the solution for CMake users:
Pass PrintSupport to the find_package call, to the right side of COMPONENTS, like in this example:
find_package(Qt5 ${QT5_MIN_VERSION} REQUIRED COMPONENTS Core Gui Qml QuickControls2 PrintSupport)
I compiled a library using the MinGW toolchain provided with Qt 5.0.2 on Windows. As a result I received a library.so file. First I failed using the library in a Qt application, but now I found out that everything works fine when I make a copy of the liblibrary.so file and call it liblibrary.dll or liblibrary.lib (which is the only file ending supported by the add library wizard in QtCreator).
Now I wonder if this is normal or if I should change something in order not to have both files (which are exact copies). Leaving one away makes the application crash during start up. I added the library as follows to my Qt pro file:
LIBS += -L"../path/to/library" -llibrary
INCLUDEPATH += $$quote(../path/to/library)
EDIT: I compiled the library using the MinGW of Qt, not as Qt project but using mingw32-make and the provided Makefile. As a result I get the liblibrary.so.
EDIT: It seems to work also when renaming the copy to liblibrary.dll instead of .lib. But still, I need two files to make the application work -- the .so and the .dll.
Chris
That's weird, I think you should get a *.a and *.dll files when building a shared lib with MinGW on Windows, as said in the documentation:
In windows, MinGW will output .a and .dll, MSVC2010 will ouput .lib and .dll. In linux, MinGW will output .so, .so.1, .so.1.0 and .so.1.0.0 – .lib, .a and .so are import libraries.
You definitely shouldn't rename your file!
Be careful to:
not to include the "lib" prefix after "-l" in your project file.
put everything after after "-l" in lower case as you're on Windows
not adding any extension to your library name after "-l"
add and reference the .h file used in your library
A real example using QtWebsocket lib:
INCLUDEPATH += "$${PWD}/include/"
LIBS += -L"$${PWD}/libs/" -lqtwebsocket
...
HEADERS += ... \
$${PWD}/include/QWsSocket.h \
...
In my include/ folder, I have the following file:
QWsSocket.h (taken from original project - required)
In my libs/ folder, I have the following file:
libQtWebsocket.a
QtWebsocket.dll
Edit: I struggled with this too initially. Have you tried to build your lib as a static lib instead (CONFIG += staticlib in your library project)? This might help you getting you *.pro file right before switching to using the shared library.
Edit 2: Ok, the fact that you get a *.so file is still a bit odd. In this question
the user has the same issue as you and keep both files, which is just a workaround. According to a later answer it seems that you need to modify your makefile to generate a file with the proper extension. Maybe this will help: http://www.mingw.org/wiki/sampleDLL
I made a custom library and i compiled it into a dll (qustom.dll).
Now i want to compile another project using this dll.
What i did is to import the header files in the project and add this line in my .pro file
LIBS += -lqustom
but i get "error: cannot find -lqustom"
also i tried
LIBS += qustom.dll
and
LIBS += -libqustom.a
qustom.dll is in the project directory
Also i tried
OTHER_FILES += \
qextserialport1.dll
but didn't work either
Am i missing something here?
Missing a path perhaps? -L/path/to/dlls -ldllname
Qt plays nicely with CMake. I use that and I never get dependency/path headaches like this any more.
I have a shared library (with no QT dependency) [library B] that links to another shared library (with no QT dependence as well) [library A].
I am using Qmake and QT Creator 1.3. The problem is that when I build library B and run ldd on the executable, it is being linked to QtCore and QtGui, both of which are pulling in lots of unrequired files, resulting in an executable that is taking long to load, and has unwanted dependencies.
I have tried just about everything to stop qmake from linking these libraries to library B.
A snippet of my project file for library B is shown below:
TEMPLATE = lib
LIBS += -L../datelib/bin -ldatelib_release
QT -= gui core
LIBS -= -lQtGui -lQtCore
CONFIG += dll
CONFIG += debug_and_release
CONFIG(debug, debug|release) {
TARGET =targetnameD
}else {
TARGET = targetname
}
I am using QtCreator 3 on Ubuntu 9.10
QT is version 4.5.2
Put CONFIG -= qt in your .pro file.
You can try with
CONFIG += dll
QT -= gui core
LIBS -= -lQtGui -lQtCore
For apps, you do it like this:
TEMPLATE = app
CONFIG = console
More info here:
qmake common projects
I had similar problem.
What I did was to create new library project with out qtcore and qtgui. Removed all unnecessary files that was created by wizard. Added my files to project folder and modified the *.pro file. It started to work correctly.
It was some problem with QtCreator, it not read correctly .pro file generating .pro.user, witch QtCreator use to build, and wizard generate correct .pro.user file.
I did this with Qt 4.7
Wish this help.
As far as I know, Qt creator doesn't take the .pro configurations into consideration if you don't have them set up separately from the IDE.
You should go to the project's settings, clone the debug configuration, rename it release, set the QMake build configuration to release(!) and change other settings as you see fit. Then you can pick which configuration to build from the IDE.
P.S: Try using Qt Creator 1.3.1 as it fixes a lot of bugs and brings interesting new features.