CMake Manual

Getting Started

The first requirement when using CMake is to use find_package to locate the libraries and header files shipped with Qt. These libraries and header files can then be used to build libraries and applications based on Qt.

The recommended way to use Qt libraries and headers with CMake 2.8.8 is to use the qt5_use_modules command.

To build a helloworld executable, typical usage would be:

 cmake_minimum_required(VERSION 2.8.8)

 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.
 qt5_use_modules(helloworld Widgets)

Note that it is necessary to use find_package to find a Qt module before using the macro. See the documentation for the CMake find_package Documentation command for the full options it supports.

In order for find_package to be successful, Qt 5 must be found below the CMAKE_PREFIX_PATH, or the Qt5<Module>_DIR must be set in the CMake cache to the location of the Qt5WidgetsConfig.cmake file. The easiest way to use CMake is to set the CMAKE_PREFIX_PATH environment variable to the install prefix of Qt 5.

The qt5_use_modules command encapsulates all of the variable usage required to use a Qt module. It automatically finds the modules given to it on the command line if they have not already been found.

 find_package(Qt5Core)

 # Find the Widgets Sql and Network modules, and
 # use them in helloworld.
 qt5_use_modules(helloworld Widgets Sql Network)

The CMAKE_AUTOMOC setting runs moc automatically when required. For more on this feature see the CMake AUTOMOC documentation

 find_package(Qt5Core)

 get_target_property(QtCore_location Qt5::Core LOCATION)

 find_package(Qt5Core)

 set(CMAKE_CXX_FLAGS_COVERAGE "${CMAKE_CXX_FLAGS_RELEASE} -fprofile-arcs -ftest-coverage")

 # set up a mapping so that the Release configuration for the Qt imported target is
 # used in the COVERAGE CMake configuration.
 set_target_properties(Qt5::Core PROPERTIES MAP_IMPORTED_CONFIG_COVERAGE "RELEASE")

 cmake_minimum_required(VERSION 2.8.3)

 project(testproject)

 # Find includes in corresponding build directories
 set(CMAKE_INCLUDE_CURRENT_DIR ON)

 # Find the QtWidgets library
 find_package(Qt5Widgets)

 # Add the include directories for the Qt 5 Widgets module to
 # the compile lines.
 include_directories(${Qt5Widgets_INCLUDE_DIRS})

 # Use the compile definitions defined in the Qt 5 Widgets module
 add_definitions(${Qt5Widgets_DEFINITIONS})

 # Add compiler flags for building executables (-fPIE)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${Qt5Widgets_EXECUTABLE_COMPILE_FLAGS}")

 qt5_generate_moc(main.cpp main.moc)

 # Tell CMake to create the helloworld executable
 add_executable(helloworld main.cpp main.moc)

 #Link the helloworld executable to the Qt 5 widgets library.
 target_link_libraries(${Qt5Widgets_LIBRARIES})