CMake in the project#

Tip

Useful to know: CMake Configuration vs Build Steps

Configuration-Time Commands

  • configure_file(…): Generates config headers.

  • file(COPY …): Copies files during configuration.

  • set(…): Defines variables used in build logic.

  • execute_process(COMMAND …): Executes an executable.

Build-Time Commands

  • add_library(…): Defines targets built during the build step.

  • add_executable(…): Defines targets built during the build step.

  • target_link_libraries(…): Links libraries during build.

Basic CMake commands:

message("Output directory: ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}")

Prints the given string and/or CMake variable to the console.

cmake_minimum_required (<version_no>)

  • Sets the minimum required version of cmake for the project. It will affects the way of cmake configuration and build process.

  • It is necessary to invoke this command at the beginning top level of CMakeLists.txt file before invoking any other command.

cmake_policy (<version_no>)

  • It will mention cmake to use the new or old behavior of the mentioned <policy_no>.

  • And also cmake_minimum_required() will implicitly invokes this command.

set(CMAKE_CXX_STANDARD <standard_no>)

This command will set the C++ standard to given <standard_no>.

$ENV{env_var}

ENV is an operator through which we can read the value of the given environment variable <env_var>.

if(DEFINED env_var) or if (NOT DEFINED env_var)
endif()

To check whether the env_var was defined or not.

add_compile_options(<option>)

It will add options which will be used to get compiled for targets.

find_package(<package_name>)

  • cmake will find the mentioned package and will load its package specific details.

  • example : find_package(Threads).

CMake commands to build the projects:

add_subdirectory(<sub_directory_name>)

It adds the mentioned <sub_directory_name> to the cmake build process.

project(project_name)

It sets the project name and stores in the given variable <project_name>.

include_directories(<directory_name>)

  • The include files which are stored in given <directory_name> or environment variable will be added to the cmake build process.

  • example include the framework headre files:

    include_directories(${SDV_FRAMEWORK_DEV_INCLUDE}).

execute_process(COMMAND <command1> <argument1> <argument2> ....)

It executes one or more child processes or commands sequentially. Since the command runs an .exe, no intermediate command interpreter is executed. It is widly used to auto generated code with sdv_dbc_util and sdv_vss_util.

file (COPY <filename> DESTINATION <destination_directory>)

  • Copies files during configuration.

  • Mainly used to copy the configuration files to the output sub folder.

  • example to copy a configuration file:

    file (COPY ${PROJECT_SOURCE_DIR}/config/CanComSimulation.toml DESTINATION ${CMAKE_BINARY_DIR}/bin/config).

add_custom_target(<target_name>
ALL
DEPENDS
    <dependencies>
    ....
COMMAND <commands>
VERBATIM
)

  • It will adds a target with the mentioned name and will executes the mentioned commands.

  • This target will be added to the default build target, so it will run every time.

  • when the target was built, the mentioned dependencies also will be updated.

  • example:

    add_custom_target(example_interface_config ALL DEPENDS can_dl_example COMMAND “${SDV_PACKAGER}” DIRECT_INSTALL ExampleInterfaceComponents –instance3001 can_dl_example.sdv VERBATIM )

add_dependencies(<target> <target-dependency>...)

  • It will make sure that mentioned top level dependency target got compiled before <target> does.

  • example: add_dependencies(example_application ExampleGeneralComponent ExampleAccessToOtherComponents).

add_test(NAME <test_name> COMMAND <command>)

  • Adds a test called <test_name> to the project.

  • enable_testing() command should be invoked in order to generate tests by cmake.

  • example : add_test(NAME configuration_example COMMAND configuration_example).

Build SDV binaries:

add_library(<target_name> <type>
<path_to_include_files>
<path_to_source_files>
)

  • This command will add a library which was mentioned as demo_complex_service which will be built from the given source and include files.

  • type - SHARED or STATIC or MODULE : The mentioned library will be created as a dynamic or static or module based library.

  • example : add_library(ExampleVehicleDevice SHARED Code/Example_VehicleDevice.cpp).

set_target_properties(<target_name> PROPERTIES <property1> <value1>)
set_target_properties(<target_name> PROPERTIES <property2> <value2>)

  • It sets the properties of values which will affects the given one or more targets.

  • example for the sdv binaries:

    • set_target_properties(<target_name> PROPERTIES SUFFIX “.sdv”).

    • set_target_properties(<target_name> PROPERTIES OUTPUT_NAME “door_complex_service”)

    • set_target_properties(<target_name> PROPERTIES PREFIX “”)

Build SDV executables:

target_link_libraries(<executable_name> <lib1> <lib2> <lib3>)

  • It links all the mentioned libraries to the given target.

  • example : target_link_libraries(system_extern_example Ws2_32 Winmm Rpcrt4.lib).

add_executable(<executable_name>
<path_to_source_files>
)

  • It creates an executable which will be built from the mentioned source and include files.

  • example: add_executable(system_extern_example example_app/system_extern_example.cpp).