[SOLVED] Complete but simple CMake example

markc

Would anyone know of a complete but SIMPLE example of using CMake with a QtCore based non-gui console application, preferably on Github?

I'm aware of this article and it even suggests source code but I can't find a link.

http://developer.qt.nokia.com/quarterly/view/using_cmake_to_build_qt_projects

markc

Here is a minimal console application example (main.cpp) with a CMakeLists.txt to build it...

@#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
qDebug() << "Hello CMake";
return a.exec();
}@

@# mkdir build && cd build

cmake .. && make

sudo make install

cmake_minimum_required(VERSION 2.8)
project(hello_cmake)
set(SRCS main.cpp)
find_package(Qt4 REQUIRED)
include(${QT_USE_FILE})
add_executable(hello_cmake ${SRCS})
target_link_libraries(hello_cmake ${QT_LIBRARIES})
install(TARGETS hello_cmake DESTINATION /usr/bin)@

JohnKaul

Since the comments in the above CMakeLists.txt file suggest in-souce builds are not allowed, I would add that check to the file.

I also like to use the PROJECT_NAME variable instead of retyping out the name of my project.

The last snip is for the INSTALL location.

@cmake_minimum_required(VERSION 2.8)
project(hello_cmake)

Do not allow in-source builds:

if(CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
message(FATAL_ERROR "In-source builds are not allowed.")
endif()

... <SNIP> ...

add_executable(${PROJECT_NAME} ${SRCS})

... <SNIP> ...

if(UNIX)
install( TARGETS ${PROJECT_NAME} DESTINATION /usr/bin)
# And in addition, maybe?
# else(WIN32)
# install(
# TARGETS ${PROJECT_NAME}
# DESTINATION "C:/Program Files/${PROJECT_NAME}"
# )
endif()@

markc

From one Lab Rat to another, thank you and welcome to the forums :-)

Nice additions. Love the in-source build test.

I think the install DESTINATION path is relative to CMAKE_INSTALL_PREFIX so "/usr/bin" should probably be just "bin" and allow the cmake -Dvar or env var to set the actual install path. The critical part that I was missing that got me to ask the question turned out to be this line...

@target_link_libraries(${PROJECT_NAME} ${QT_LIBRARIES})@

or more specifically, a missing reference to QT_LIBRARIES. Related questions, how to emulate these QMake settings?

. OTHER_FILES=
. CONFIG += console
. QT -= gui
. CMAKE_INSTALL_PREFIX=/usr

JohnKaul

I apologize for not getting back to you right away (I've been busy).

Thank you for the welcome.

[quote author="markc" date="1325270450"]...<snip>...

Related questions, how to emulate these QMake settings?

. OTHER_FILES=
. CONFIG += console
. QT -= gui
. CMAKE_INSTALL_PREFIX=/usr
[/quote]

I think this may be what you are looking for.
http://developer.qt.nokia.com/doc/qt-4.7/qmake-environment-reference.html#id-4c6e9803-1d05-47bd-baa7-e139fd2adbd3

However, I am not all that good with qmake so I could be way off. Sorry if that isn't what you were looking for or is just totally wrong.

aaichert

For Qt5, the CMakeLists.txt should be
@
cmake_minimum_required(VERSION 2.8.11)

project(testproject)

Find includes in corresponding build directories

set(CMAKE_INCLUDE_CURRENT_DIR ON)

Instruct CMake to run moc automatically when needed.

set(CMAKE_AUTOMOC ON)

Find the QtWidgets library

find_package(Qt5Widgets)

Tell CMake to create the helloworld executable

add_executable(helloworld main.cpp)

Use the Widgets module from Qt 5.

target_link_libraries(helloworld Qt5::Widgets)
@

"http://qt-project.org/doc/qt-5/cmake-manual.html":http://qt-project.org/doc/qt-5/cmake-manual.html

aaichert