Calling existing make command in cmake file

Question

I have a large project with multiple subdirectories. In the parent directory, I have a CMakeLists.txt file which calls functions defined in other cmake files in the same parent directory. I have a custom Makefile in one of the subdirectories that contains some target "run". When I call cmake from the parent directory, I want the "run" target located in the subdirectory makefile to execute. How should I do this ?

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I understand that some people have suggested to use add_custom_target and add_custom_command, but I am still confused as to how to apply these commands to accomplish this task.

Answer 1

If you know, which file(s) are produced by Makefile in the subdirectory, and want to depend on these files, use add_custom_command:

add_custom_command(OUTPUT <output-file>
                   COMMAND make run
                   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/<subdir>
)

This assumes that your CMakeLists.txt have a target, which depends or uses given file.

Otherwise, if you do not care which files are produced by Makefile, use add_custom_target:

add_custom_target(<target_name> COMMAND make run
                   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/<subdir>
)

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In both cases WORKING_DIRECTORY specifies directory which should be current for command executed.

If you want the target (in the second case) to be executed by default, add ALL option before the COMMAND.