I am creating new project using cmake to configure it. That project has dependency of library lib1, for example which is compiled separately.
Problem starts when I add include folder of the lib1 like this:
include_directories (../lib1/include)
When I launch make command it complains saying that
fatal error: 'QSharedData' file not found
#include < QSharedData >
QSharedData is included in one of the .h of lib1.
How can I fix this?
Thanks in advance
You should definitely follow Qt's cmake instructions (https://doc.qt.io/qt-5.10/cmake-manual.html) and use their cmake package, i.e.
find_package(Qt5Core)
...
The Qt cmake package takes care of determining and setting the needed include directories, etc.
Related
I have a QT Project I am working on, it has a couple of sub-modules, which I list in my project's .pro file as:
if(!include(module/my_module.pri)){
error("module my_module not found")
}
What I tried:
Well, I have found a library which I intend to use, which is a CMake project libcrashreporter-qt. I am just linking the project for completeness - there is nothing wrong with this library (to my knowledge)
Problem:
I figured I will try an include the CMakeLists.txt file as I would a .pri file:
if(!include(libcrashreporter-qt/CMakeLists.txt)){
error("module libcrashreporter-qt not found")
}
where the libcrashreporter-qt folder is in the root of my project
Some Code:
In doing so, I get a horde of compiler errors:
$project_dir/libcrashreporter-qt/CMakeLists.txt:1: 'project' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:2: 'cmake_minimum_required' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:4: Extra characters after test expression.
$project_dir/libcrashreporter-qt/CMakeLists.txt:5: 'cmake_policy' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:6: 'endif' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:10: 'find_package' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:12: Opening parenthesis without prior test name.
$project_dir/libcrashreporter-qt/CMakeLists.txt:16: 'string' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:17: 'string' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:18: 'endif' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:20: 'add_subdirectory' is not a recognized test function.
$project_dir/libcrashreporter-qt/CMakeLists.txt:21: 'add_subdirectory' is not a recognized test function.
CMake file content (note, I changed the file slightly trying to resolve build issues by removing the multi-line if-statement and commented the option line):
project(libcrashreporter-qt)
cmake_minimum_required(VERSION 3.1)
if(POLICY CMP0071)
cmake_policy(SET CMP0071 NEW)
endif()
#option(ENABLE_GPL_CODE OFF)
find_package(Qt5 COMPONENTS Core Network Widgets)
if((CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_FLAGS) OR (UNIX AND NOT APPLE AND CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
# Breakpad uses GNU compiler extensions like typeof.
# Luckily these features are not used on OSX, so we can build the
# crashreporter there with the normal C++11 standard.
string(REPLACE "-std=c++11" "-std=gnu++11" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
string(REPLACE "-std=c++14" "-std=gnu++14" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
endif()
add_subdirectory(3rdparty)
add_subdirectory(src)
This leads me to believe there is an issue with Qt .pro file compatibility and CMake projects being used within each other.
Question:
How can access the library functions of this CMake project, and compile it with my project (i.e. w/o changing the CMake project itself), or alternatively how best can I convert the CMake project to a compatible .pro project?
AFAIK CMake and QMake cannot be mixed together in one project, they are two different build systems and if you want to use a CMake project in a QMake project you have "two" options:
if you want to use the source files (.cpp and .h) or even modify them in your project you have to import them to your QMake project (you can easily do that in your QtCreator) and compile all of the files of your project
if the CMake library that you are using doesn't need any change (most of the times it's like this when you're using a third party library) and you just want to import it to your project and link it against your executable, you just run and compile the CMake project (separate from your own QMake project) and then use the output dynamic or static library of that project to link against your QMake project
As far as I remember, in Qt you can specify the custom compiler settings for the extra target, so, if you need your CMake project to be rebuilt just before the target Qt application is built, you can try to use this way
A possible solution is here:
https://stackoverflow.com/a/15766946/2333496
It appears that libwebsocket is the only library that does not come with Qt, so I think I need to compile it and install it in my QT folder so I can use with other things.
I tried to compile libwebsocket and I got this error:
qwebsocket_p.h:65:10: fatal error: private/qobject_p.h: No such file or directory
#include <private/qobject_p.h>
I believe this is because the QT in my system is old. I have a QT installation in my home folder. How should I pass it to websocket?
If it were with cmake I'd have an idea, but I've heard here https://stackoverflow.com/a/49108604/10116440 that you cannot pass qt folder to qmake. Is there a way to pass to make?
I also tried doing this in cmake:
find_package(Qt5WebSockets REQUIRED)
find_package(Qt5 COMPONENTS Core Qml Quick Svg)
this way I can do cmake -DQt5_DIR=/home/lz/Qt5.11.2 . to set the Qt5 variable for everything except Qt5WebSockets, but the project fails to include <QWebSocket> anyway. If someone knows how to solve this, it'd also be good
private/qobject_p.h: No such file or directory
That means that the directory containing qobject_p.h was not added to the Include paths list. Make sure that your .pro has QT += core-private string.
I have a QT installation in my home folder. How should I pass it to websocket?
It should be enough to put the file named qt.confto the directory containing qmake.exe:
qt.conf
[Paths]
Prefix = <qt root>
I use Qt with CMake because CMake integrates with my team's work easier than my own. I have frequently encountered an error along the lines of
ui_*.h: No such file or directory
Usually when my project already has a ui_*.h file to start with it will just modify that .h file. I do use the below commands in my CMake file, so it should be wrapping my .ui file with the appropriate ui_*.h file.
qt4_wrap_ui (mainwindow mainwindow.ui)
target_linked_library (mainwindow ${QT_LIBRARIES})
But sometimes that doesn't work and I have to completely rebuild the entire ui_*.h file. What am I doing wrong?
For anyone having this problem in the future. I pretty much followed the demo here.
http://doc.qt.io/qt-5/cmake-manual.html
Adding, the following line to the CMakeLists.txt should get rid of this problem.
set(CMAKE_AUTOUIC ON)
From the CMake documentation at
https://cmake.org/cmake/help/v3.0/prop_tgt/AUTOUIC.html
AUTOUIC is a boolean specifying whether CMake will handle the Qt uic code generator automatically, i.e. without having to use the QT4_WRAP_UI() or QT5_WRAP_UI() macro. Currently Qt4 and Qt5 are supported.
One small note, this property is available in CMake versions 3.0.2+. So below that, #rbaleksandar's solution should be more appropriate.
Hope that helps.
The quick solution is to use UIC. In bash navigate to the directory containing your *.ui file and run (for the mainwindow.ui example)
uic mainwindow.ui -o ui_mainwindow.h
and then move the newly generated ui_mainwindow.h file to your build directory.
mv ui_mainwindow.h ../build_Qt_4_8_5-Debug/
You shouldn't see the 'No such file or directory' error anymore and can confidently move on to the many other wonderful errors to find in the world of Qt with CMake.
If I remember correctly you actually have to add your UI files to the add_executable(...) like this:
qt4_wrap_ui(UI_HEADERS mainwindow.ui ...) # Add all UI files here like you've done it
...
add_executable(${PROJECT_NAME} ${SRC} ${UI_HEADERS}) # Add them to the executable
...
After all UI files are actually converted to header and source files, which naturally have to be compiled along with the rest of your code.
Building with CMake seems to have an error in
if(CMAKE_VERSION VERSION_LESS "3.7.0")
set(CMAKE_INCLUDE_CURRENT_DIR ON)
endif()
remove if in your CMakeLists.txt like this:
set(CMAKE_INCLUDE_CURRENT_DIR ON)
This works in my system with CMake 3.12.1 and Windows 10.
when the ui files are stored in a different location the CMAKE_AUTOUIC_SEARCH_PATHS can be set to include the custom locations so that the CMAKE_AUTOUIC option will find the ui files.
None of the previous answers have helped me.
I tried Ctrl + RMB on #include "./ui_mainwindow.h" in Qt Creator and after that the error did not appear since.
Few details to mention:
set(CMAKE_AUTOUIC ON) was enabled before add_executable()
cmake_minimum_required(VERSION 3.5)
I was using qt6
I have downloaded qt-5.0.0 for windows.
http://releases.qt-project.org/qt5/5.0.1/qt-windows-opensource-5.0.1-msvc2010_32-x86-offline.exe
I have added INCLUDEPATH += C:\opencv\build\include in the .pro file.
Opencv 2.4.3 is already installed.
When I include header file in qtcreator :
#include <opencv2/opencv.hpp>
There is compilation error : can not find opencv2/opencv.hpp
Any ideas ??
I found the solution. In Qt Creator, goto Projects on the left pane ( ctrl+5), then Build Environment -> Use System Environment, click on Details. Edit LIB variable. Add here.
Things to check:
does C:\opencv\build\include\opencv2\opencv.hpp actually exist?
does the compile command (which you can check in the Qt Creator "compile output" window) show -IC:\opencv\build\include argument in the compile command?
qmake should be run automatically after modifying the .pro file, but re-run it manually just in case (for example from Build menu), as suggested by the first answer
this should not have any effect in issue like this, but just in case: if you are using "shadow build" (which is a good idea), make sure the source dir is clean of any generated files
The correct header files are:
<opencv2/core/core.hpp>
<opencv2/imgproc/imgproc.hpp>
<opencv2/highgui/highgui.hpp>
… and so on. The include of "opencv.h" is deprecated!
It also does not work anymore for QtCreator auto-completion.
The solution is to update your sources to use the correct header files.
After any change made to .pro file , Do right-click on project folder and click on run qmake .
Well, I just ran into this problem tonight. luckily enough, after taking a fair time, the solution was found. If your project is managed by qmake, and Qcreator is used, just go to the Build->Run qmake, then build and run your project. A tip, whenever you change your *.pro file, remember to rerun Build->Run qmake, because that will reconfigure your project.
If this helps you, please give me a thumb up :)
I'm trying to subclass from ProjectExplorer::ProjectExplorerPlugin but I'm getting error telling me about undefined references. Any ideas how to fix it?
class MyPluginPlugin : public ProjectExplorer::ProjectExplorerPlugin
{
Q_OBJECT
...
};
error: undefined reference to `imp__ZN15ProjectExplorer21ProjectExplorerPluginC2Ev'
The fact that you don't get a compilation error, but an undefined reference usually means that your project knows where the header files are, but it doesn't know where the library is which contains the already compiled source code.
I've never written a plugin for Qt Creator but I've taken a quick look at its source code structure and I see the following options:
Option A)
There is a projectexplorer.pro file in Qt Creator's source under src/plugins/projectexplorer. You could manually build that project in order to get a ProjectExplorer.lib (plus a .dll or a .a) and then reference this library.Example: Assuming the library would be created in the same directory as its .pro file (I have no idea if it is like that) and you created your plugin withing Qt Creator's source under src/plugins/myplugin, you would define your LIBS variable like this:
LIBS += -L../projectexplorer \
-lProjectExplorer
The first line adds "../projectexplorer" as an additional library directory and the second line adds "ProjectExplorer" as a library to search in any of the defined directories (it automatically adds the OS-specific file extensions like .lib on windows etc).
Obviously if your project or the library is located somewhere else, you need to change the first line accordingly.
Option B)
You could include the source and header files of the projectexplorer directory to your own .pro file using the HEADERS and SOURCES variables. I'm not sure if this wouldn't interfere with any other plugins (including projectexplorer itself) though.
Option C)
There probably is a way to include the projectexplorer.pro file so that you have a master project which first builds the project explorer library and then your own plugin. This would be the safest way to go as it ensures the Project Explorer library is built and up-to-date before your own project is linked against it.
However I have limited experience on this.
If anyone reading this can give a detailed explanation on this option, feel free to edit or provide your own answer.
If you are using Qt Creator built from source coded after April 2013 which includes Commit: #66a3553 - make library and plugin dependencies declarative, then you can simply specify dependencies for your plugin in its .pro file:
# myplugin.pro
QTC_PLUGIN_DEPENDS += \
coreplugin \
projectexplorer