In this recipe, we achieved the execution of CMake code at build time. For this, we defined a custom command:
add_custom_command( OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/generated/version.hpp ALL COMMAND ${CMAKE_COMMAND} -D TARGET_DIR=${CMAKE_CURRENT_BINARY_DIR} -P ${CMAKE_CURRENT_SOURCE_DIR}/git-hash.cmake
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} )
We also defined a custom target, as follows:
add_custom_target( get_git_hash ALL DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/generated/version.hpp )
The custom command invokes CMake to execute the git-hash.cmake CMake script. This is achieved by using the -P CLI switch, to pass the location of the script. Notice that we can pass options with the -D CLI switch, as we usually would. The
