Install targets for cotire generated unity builds about cotire

[sakra]

cotire cannot set up a install_unity target automatically, because CMake does not provide the necessary information about the existing install(TARGETS target) programmatically. You can however set one up manually. First add an install rule for each unity target, e.g.:

install(TARGETS example_unity RUNTIME DESTINATION "bin" OPTIONAL COMPONENT "unity")

This installs the example executable built by the unity target to the bin folder. The install rules for unity targets must use a custom install component. You can then add a global unity_install target that performs the installation of all unity targets:

add_custom_target(unity_install
        COMMAND ${CMAKE_COMMAND} -DCOMPONENT=unity -P cmake_install.cmake
        COMMENT "Install the unity-built project..."
        WORKING_DIRECTORY "${CMAKE_BINARY_DIR}")
add_dependencies(unity_install example_unity)

The global unity_install target must depend on all unity targets that should be installed.

[peterhuene]

We ran into a similar problem for our CI that uses unity to speed up builds. We elected to run the install/fast target after the all_unity target as two discrete steps; the install/fast target performs the install target without dependencies.

This allowed us to not have to define a different install target for unity builds.

[sakra]

Section has been added to the manual in cotire 1.6.7.

[jcelerier]

Another possibility that @ngladitz taught me was to remove the dependency on the all target to the install target :

set(CMAKE_SKIP_INSTALL_ALL_DEPENDENCY True)

The big advantage is that this allows running cpack easily with the unity targets (else cpack calls make install which just rebuilds everything).